LONDON: Online ads accounted for 28% of complaints made to the Advertising Standards Authority (ASA) in 2012, with work in this area "growing exponentially", the UK regulatory body has revealed.

This rise in digital complaints follows the extension of the industry regulator's online remit in March 2012 to encompass marketing that appears on advertisers' own websites, Twitter feeds, Facebook pages and apps.

While television remained the most complained-about medium, the ASA's annual report noted that there were "a higher number of marketing communications complained about on the internet" compared to on television.

In all, there were complaints about 18,990 ads, of which 5,338 were broadcast online. The majority of these complaints were due to misleading ads, which constituted 70% of cases, the remainder being divided between allegedly offensive ads and harmful ads.

The ASA also identified its five misleading advertising priorities, which included free trial offers where "customers were unwittingly tied into an on-going paid relationship with an advertiser".

It said that its actions on misleading pricing had already resulted in greater transparency in hotel pricing, where VAT was now included in advertised room rates, and in telecoms packages that bundled several services together such as broadband, line rental, call costs and TV.

Similarly, action on "daily deals" had led to improvements in the way these promotions were conducted, as companies had failed to make clear terms and conditions and had made exaggerated claims about the possible savings, the ASA claimed.

Misleading testimonials was the fourth area addressed, with ASA rulings on the issue of celebrity tweets leading to the requirement for advertisers to make it obvious when a tweet is a paid-for commercial message.

Finally, the ASA said it was concerned about misleading health claims, many of which were made online and which it feared could discourage people from seeking proper medical advice.

"Making sure that responsible advertising isn't being under-cut by the irresponsible helps get a fair deal for consumers and competitors," added Lord Smith, chairman of the ASA.

"Misleading ads hoodwink consumers, give an unfair advantage to businesses that don't play by the rules and erode trust in advertising," he added.

Data sourced from Advertising Standards Authority; additional content by Warc staff