From 1 March 2011, the Advertising Standards Authority (the ASA) will regulate all advertisements online as well as in print and broadcast media including, for the first time, marketing messages on companies' own websites and on non-paid-for services under their control, including social media platforms such as Twitter, Facebook and LinkedIn.

Online advertising is a big and growing business, increasingly influential given the sheer amount of time that we all spend on the web, the ease in which we can click on a link if we actually want to purchase the product or service in question and easy to quantify in terms of return on investment; the trend appears to be that online advertising is better value for money. Previous figures suggest that the public has been making a steadily-increasing number of complaints about websites which the ASA would not previously have been able to deal with due to being outside of its remit.

‘But from 1 March, the ASA's UK Code of Non-broadcast advertising, sales promotion and direct marketing (the CAP Code) will apply in full to ‘marketing communications connected with the sale or transfer of goods or services online’, regardless of the size of the business in question or the sector in which it operates. So, any complaints concerning misleading advertisements for (by way of example) a flight abroad which costs significantly more when paying than the price advertised on the airline's homepage may well lead to them being withdrawn.

The definition of ‘marketing communications’ is significant in itself, as it includes material on a business' own website as well as communications on platforms that they don't pay for but do control. This means that marketing communications on Twitter, Facebook or any other social network will now be covered by the CAP Code and can be subject to sanction by the ASA. Social network comments can even be covered even where made by private individuals when the business in question adopts them as a marketing communication, although the average positive comment quoted on a homepage will not usually fall under the expanded CAP Code.

The ASA is sometimes seen as a little toothless in that the sanctions it can impose for advertisements which fall foul of the CAP Code don't include the ability to award damages to a complainant. There are, however, other options open to them which tend to produce a high level of compliance, such as denial of advertising space to repeat offenders and the publication of upheld complaints by way of the adjudication process. The new sanctions available under the ASA's digital remit have more bite than bark and may well reach a much wider audience than tend to read their adjudications – if a ‘marketing communication’ on a website falls foul of the ASA's CAP Code, then the business responsible can now be subject to an enhanced name and shame policy via the ASA's website (which may well show up at the higher end of search results when published), the removal of paid for and sponsored search results that link to the advertisement in question (affecting SEO strategy and general online visibility) and an appearance in the ASA's own paid-for advertisements on search engines publishing the details of serial offenders.

Even though the ASA system relies on self-regulation, search engines have already indicated that they will co-operate with the new rules, which could make the new sanctions much more powerful.

Online advertisements should now be drafted with an eye towards the CAP Code - complaints to the ASA are sometimes harder to dismiss than the member of staff who posted the offending material. The Code itself aims to make advertisements honest, decent, truthful and legal and contains specific guidance on content. Complaints can be made by anyone, whether members of the public or rival businesses; many adjudications centre around the cosmetics industry, with L'Oreal being recently found to have exaggerated claims as to the length of cosmetic eyelashes and Argos found to be in breach over claims that they could deliver to their customers at a time convenient to them. Both advertisements were withdrawn.

‘There are some exceptions – press releases and PR material will not be covered, nor will editorial content and ‘natural’ (i.e. not paid-for) appearances in search results and on price comparison sites. That said, there are some basic steps which businesses should take to ensure compliance, including employee training, active management of sites and campaigns and making use of the ASA's own CopyAdvice service, but the best thing to do is take advice as soon as possible and, if in any doubt, remove the advertisement.

Although it's argued that the web is still relatively lawless, this is a clear example that laws applicable in the offline world apply equally online. The online world tends to contain some very loud and active voices, and news of an advertisement which is found to have been misleading under the CAP Code can spread worldwide at the click of a mouse. Even though news of ASA involvement may fade away like any other blog post over time, details on the web can still remain on search engines for some time to come and prevention through compliance is far better than a cure involving spending time and money on PR and search engine marketing. Misleading advertisements may now force your business to literally pay per click.