Google plans to introduce cost-per-click (CPC) ad buying in March, to give another payment option to its advertisers who use AdWords to place display ads on select sites, reports MediaPost.

Google said it is looking for marketers willing to take part in a test of the CPC program. For now, display advertisers can purchase ads on a only cost-per-thousand (CPM) basis when using the site-targeting option to select specific sites on which to place their ads.

Some advertisers have been asking for a CPC option as they look for more flexibility in their ad planning; others have simply been reluctant to pay on a CPM basis.

Display advertising is popular with marketers whose emphasis is branding and/or direct response, and CPC makes those programs more easily quantifiable.