A group of online marketers and search engines have issued a list of principles claiming what is needed for an effective pay-per-click (PPC) advertising campaign.

The Click Quality Council believes that advertisers should have control about where their PPC adverts are targeted based on criteria such as location, time and specific users.

Director of search marketing firm Avenue A / Razorfish Matt Greitzer said: "As search engines and industry groups work on the development of click quality standards, it's important they know the key principles advertisers believe should be part of any initiatives."

Meanwhile, it was claimed that advertisers should never had to pay for clicks which are constantly repeated within one session or traffic which comes from bots, which could help marketers.

It was also suggested that search engine firms should provide a more transparent system for advertisers to see how their clicks are being spent.

Last week, a Click Forensics report indicated instances of PPC fraud in advertisements shown on search engines has increased over the first-quarter of 2007.

In the three-month period ending March 31st, click fraud accounted for 21.9 per cent, compared to 19.2 per cent in the last three months of 2006.