Corporate blogging is making a comeback. Once dismissed as gimmicky self-promotion, the forum is now favoured by 35 companies in Britain's benchmark FTSE100 index, according to research from corporate communications agency Addison Group.
That figure is up from the 24 uncovered by the same survey a year earlier and many commentators see corporate blogging becoming ubiquitous.
In America, everyone seems to be doing it, from Bill Marriott, the 80-year old chairman of hotels chain Marriott, to the Red Cross, Delta Airlines, Starbucks, General Motors, heavy equipment maker Caterpillar and the obvious names from the technology sector.
So what's driving this trend, what are the challenges and how are companies dealing with them?
Corporate blogs first emerged about a decade ago but faded for much the same reason as individual blogs - the lack of credible distribution networks to bring people to internet sites to read them.
Now Twitter, Facebook and LinkedIn are acting as conduits for a resurgence in corporate blogging that seeks to communicate in less formal and more personal ways with a new generation of consumers.
'Companies are now more comfortable with social media. It's just a natural extension of that,' says Mark Hill, chairman of Addison Group.
'There's been a surge but corporate blogging is now almost always done in conjunction with Twitter and sometimes also with Facebook, YouTube and LinkedIn.
'There's a big push on blogging because it's a much more flexible mechanism in terms of being able to have some kind of dialogue. It's much more personal content and more trusted than a straight press release.'
Hill says companies use blogs for three main purposes. The first is thought leadership, such as Addison Group client Centrica, which uses its blog to offer information about energy, sustainability and security of energy supply.
A second purpose of a blog is to fill information gaps. Dell, for example, has a DellShares Blog aimed at investors.
Hill says blogs are much better than press releases at connecting people with information in a way that enables two-way communications and engagement. He says: 'Our research shows that corporate sites that have blogs generate much more loyalty. The amount of content consumed on corporate sites with blogs is much higher than on corporate sites that are much more about just giving out information.'
Blogs can also be effective communication tools in a crisis, as Tesco discovered last year.
The supermarket chain had a sobering experience in 2008 when Simon Uwins, marketing director of Tesco's US operations, revealed in his blog that the roll-out of the Fresh & Easy store format would slow down.
This led to a major fall in Tesco's shares, temporarily knocking about £900 million from its market capitalisation.
Four years on, group media relations director Tom Hoskin decided that Tesco should launch Talking Shop, a blog aimed at evening out the peaks and troughs of newsflow and creating a more personal and human voice. Talking Shop came into its own amid two very different controversies last year and has now had more than 230,000 page views.
One came when newspapers suggested that Tesco's investment in boutique coffee shop chain Harris & Hoole meant that the group was taking over the High Street by stealth. A few weeks later, the horsemeat mislabelling scandal broke.
'With Harris & Hoole, we thought we could use the blog to respond fully, rather than trying to condense our entire approach in two lines that we felt would be quotable in a news story,' says Hoskin.
'We thought we'd do a blog instead and the amazing thing was that a lot of the coverage quoted it in full or very nearly in full.
'When we hit the horsemeat affair a few weeks later, that was a useful prompt to us. The blog really came into its own in being able to reflect the very real human emotions we felt about this thing having happened and our absolute conviction that we were going to do everything that we could to ensure it didn't happen again.'
Chief executive Phil Clarke wrote that blog but the supermarket group now has 24 authors, ranging from store managers to Paul Wilkinson, a graduate in Tesco's technology team who blogged about going to America to find out about 3D printing.
The corporate communications office does not write the blogs, although Hoskin admits it sometimes helps the authors. 'The underlying movement is towards communicating more,' he explains. 'We wanted to humanise the brand. People tend to look at big organisations as being rather robotic and not very human. But the trust we rely on needs to come from people trusting people, rather than people trusting an organisation.
'This isn't a faceless brand. This is about people. There just happen to be 320,000 of them in the UK. We felt that this was the best way to reconnect with the people who are responsible for making Tesco what it is and giving a voice to the people who work here.'
Plenty of challenges present themselves to companies embarking on corporate blogging, however. Hill suggests that a major one is just getting senior management to buy into the idea of blogging because they perceive it as resource-heavy.
'It needs a lot of editorial planning and you need to commit to it and keep it up,' he says. 'About two-thirds of the companies which said in our survey that they blog post about ten blogs a month.'
He advises that staff should be trained in blog writing for online audiences, as well as receive tuition on search engine optimisation techniques such as web-links and the use of video and pictures.
Another issue is who should blog. Glenn Gow, founder of Crimson Marketing, a US agency focused on technology, has spoken out strongly against chief executives' blogging, arguing in a recent blog that they should focus on supporting sales, marketing, manufacturing and finance functions.
'To make a case that a chief executive needs to be personally involved in social media is no different than making a case that they need to be personally involved in every other function of the company,' he said. 'A chief executive's main focus is to direct the activities of those who own these functions.
'I don't think they should personally spend time trying to figure out exactly how to use social media to maximise the impact of their voice. The chief executive's job is not to directly participate in social media.'
There are also conflicting views on how far consumer participation in corporate blogs should go. Hill reports: 'Almost all our clients started out not allowing comments on their blogs. They were very cautious about that because they were worried about being flooded with comments.
'But what happens is that they're not flooded. Once people have spent a few months realising they're not getting swamped with obscure queries from students in far-off places, they realise that the work overload they thought they were going to get just hasn't materialised.'
Most blogging remains a highly-controlled area, however. Addison Group's blog-building tools, for example, do not automatically publish comments made by the public on blogs. They also give the authors options on whether or not to respond to remarks made.
'There are a lot of trolls, people who spam or people who are just mischievous out there,' says Hill. 'If a comment is off-topic or not relevant, you can ignore it. That's our advice to our clients. Just be pragmatic. These days you cannot allow open publishing of corporate blogs. It's just a legal nightmare.'
That's not the experience of O2, however. The mobile telecoms group last year launched TheBlue to bring together its corporate news site with an existing consumer blog.
It carries blogs by Ronan Dunne, chief executive of O2's parent company Telefónica UK, but also posts from literally hundreds of contributors, says head of social media Kristian Lorenzon.
Recent blogs have been about sustainability and entrepreneurship but Lorenzon says they have spanned a broad array of topics including the roll-out of 4G Internet and other new technology.
'It's about an evolution in our tone of voice,' he says. 'The content is a mixture of news and views. Almost half of the articles are written in the first person. We want a lot of voices. The difference between what we do and traditional blogs is that the latter are just written by one person.'
Unlike Tesco, O2 automatically publishes all comments on its blogs.
However, users post them via their Facebook accounts which helps with accountability, and a moderator polices the site for unsuitable material.
'We're opening up conversations,' says Lorenzon. 'We want the communication to be two-way.' So far, the blog is attracting 80,000 unique visitors a month.
There are other reasons for companies to blog too. Pharmaceuticals group AstraZeneca operates three corporate blogs: LabTalk, which addresses the science, research and innovation community; a blog by its MedImmune biotechnology business; and one for its US operations.
'We have a number of people who blog on LabTalk, though they're not necessarily regular contributors,' says Esra Erkal-Paler, head of global media relations. 'We take feedback from academics and researchers.'
She says topics for Astra Zeneca's blogs range from new therapies at businesses it has recently acquired to announcements of new clinical trials.
'It's aimed mainly at people in the industry but there are general articles on there as well,' she says. 'The idea is to inform and engage our key stakeholders. That has to underline what we do.'
Pharmaceuticals and household products group Reckitt Benckiser also has a blog, which is mainly used by staff discussing their roles at the group.
Andraea Dawson-Shepherd, senior vice-president of global communication and affairs, says: 'We do it primarily for graduates and people early on in their careers, writing about what it's like working at Reckitt Benckiser for those who don't know us so they can get a sense of what the culture is like.
'That's a key differentiator for us and we think it's very important that people get an opportunity to know what we're like. That's why we do it.'
Not all companies are comfortable with corporate blogging, however, and they're not just those firms that don't have a consumer focus.
'Our current strategy doesn't include corporate blogging as a key focus,' says Rob Cadwell, senior press officer at Waitrose.
Other groups that embraced corporate blogging in the past, meanwhile, have pulled back for corporate reasons.
At mobile phones brand Orange, PR manager Conor Maples ran the @Conorfromorange account on Twitter for several years. However, he was promoted to senior social strategy manager at Everything Everywhere, following Orange's merger with T-Mobile last year and the creation of the new enlarged business. Since his promotion, the account has been renamed @OrangeUKnews and run as a simple corporate Twitter news feed.
Mat Sears, corporate communications director at Everything Everywhere, says the @Conorfromorange blog regularly attracted more than 50,000 views of videos where he would unpack new products and give video exclusive demonstrations.
Maples also blogged direct from Glastonbury to announce Orange's sponsorship of the festival, sending back footage from Somerset farmyards.
'Conor ran a blog which we used to showcase product innovation and create a profile but we no longer do it,' says Sears. 'Everything Everywhere is a really new company and a lot has changed. It does not run as a blog per se any more. Now we have a newsroom.'
The issue, says Sears, was not that the blog was not successful but simply that the creation of a new brand and company have necessitated a different approach.
'Orange is a brand that's warm, optimistic and futuristic and the blog worked really well,' he says. 'It was just Conor doing it and it worked really well but our priorities turned elsewhere with the merger and we did not have the bandwidth to take it any further.
'Now we have other priorities but I'm sure we will return to it. We've seen just how powerful it can be.'