A lot of people use Google Adsense on their websites to generate extra income. Some people earn enough to pay their web hosting costs - others earn substantially more

Basically, you sign up for an Adsense account, cut and paste some code on your website and you're done. The code displays Google ads and, whenever one of your website visitors clicks on an ad, you get paid. Simple. Good for the surfers, good for Google and good for you.

As with any online money earning technique, users try to maximise their earnings by a variety of methods - trying different types and positions of ads, different background colours, different link colours etc. Most of these techniques are accepted as fair practice by Google - but some are frowned upon.

One very common method used to increase the probability that visitors will click on the ads has been the alignment of thumbnail images beside the ads. This has always been a bit of a grey area - and Google never really gave definitive advice on whether or not it was considered to be a legitimate tactic to use.

However, Google has now made a clear statement that this is not allowable - you can see the full post at the Google Adsense Blog - but it's summarised below

AD AND IMAGE PLACEMENT: A POLICY CLARIFICATION "We've recently received a number of emails from publishers asking how we feel about the placement of images near Google ad units. There's been some confusion on this issue, and so we turned to our policy team to set the record straight."

CAN I PLACE SMALL IMAGES NEXT TO MY GOOGLE ADS? "We ask that publishers not line up images and ads in a way that suggests a relationship between the images and the ads. If your visitors believe that the images and the ads are directly associated, or that the advertiser is offering the exact item found in the neighbouring image, they may click the ad expecting to find something that isn't actually being offered. That's not a good experience for users or advertisers

Publishers should also be careful to avoid similar implementations that people could find misleading. For instance, if your site contains a directory of Flash games, you should not format the ads to mimic the game descriptions."

WHAT IF I PLACE A SPACE OR A LINE BETWEEN MY IMAGES AND MY ADS? WOULD THAT WORK? "No. If the ads and the images appear to be associated, inserting a small space or a line between the images and ads will not make the implementation compliant."

DOES THIS MEAN I CAN'T PLACE ADS ON PAGES WITH IMAGES? "You can definitely place Google ads on pages containing images -- just make sure that the ads and images are not arranged in a way that could easily mislead or confuse your visitors. For example, if you run a stock photography site with a catalogue of thumbnail images, don't line the ads up with the thumbnails in a way that could be misleading."

So, if you're a Google Adsense publisher and using this technique, you may want to remove the images - otherwise you risk having your Adsense income removed