Travel companies and search engines have been urged to play their part and help crack down on so-called click fraud for pay-per-click advertising campaigns.
The sector has recently been at the mercy of an increase in companies clicking on the sponsored links for competitors and driving up costs for advertisers and the costs of keywords.
It is estimated in some quarters that up to 25% of click costs are in fact created by fraudulent activity by rival companies or through the creation of “junk content” on Ad Words boxes within other sites.
Search engine marketing company Greenlight said the likely figure was probably around 15%, but travel companies should learn to be more vigilant with their campaigns and the search engines themselves should play a more proactive role.
“Search engines should be vetting publishers of Ad Words and travel companies should keep a close eye on what they are paying,” chief executive Warren Cowan said.
The travel sector is believed to be particularly vulnerable to click fraud because of a massive volume of products being bid on and the high value of the certain keywords.
Companies can get a sizeable return on their advertising budgets if they make the search engines aware of any suspicious activity, Cowan warned.
The use of click fraud to skew the marketing spend of rivals has been bubbling under the surface of what has so far been a lucrative and often successful method of online advertising.
But it is believed search engines are relatively powerless to stop small-to-medium scale fraud unless it is reported.
However, Cowan said there had been a willingness by search engines to leave the system unregulated but which in turn had left PPC open to abuse.