Some online businesses may get an unwelcome surprise on 1 June. Search engine giant Google, which provides thousands of advertisements to websites across the UK, may stop providing ads to certain websites on Friday.

Google's AdSense programme automatically crawls the content of your pages and delivers ads that, according to Google, are 'relevant to your audience and your site content', allowing businesses to earn money from each click of an ad.

A spokesperson at Google told SmallBusiness.co.uk: 'We're always focused on how we can make the user experience as positive as possible while still providing value to our publishers and advertisers.

'As part of this effort, we continually conduct automated and manual reviews of publishers and sites that violate our policies. In some cases, violations of our program policies will result in termination from the AdSense program.'

This means that sites that have little content but carry a great deal of advertising could be dropped from the programme, if they are deemed too ad heavy. These sites can influence search results, and may only direct consumers to advertisements or pictures related to the type of product or service in their search criteria.

The clean-up should serve to make search results more relevant to users. For legitimate online businesses, this is good news. With fewer spam sites appearing high up in the search rankings, smaller firms could find themselves in a better position to reach customers. For more information on Google AdSense, click here.

See also: Google Checkout Opens for Business