Freespee, the call-based advertising technology service, has raised €3.3m (£2.6m) of venture financing led by Sunstone Capital. It will use the funding to develop its location-based click-to-call ads, as well continuing its market expansion.

The company has also launched Freespee Ads, which offer one-click, rich-media ad placements, using location data and call-filtering tools. Freespee reaches more than 35,000 advertisers and enables post-click-to-call analytics.

“We are very excited by the opportunities in mobile click-to-call advertising, and how it can fundamentally change the way both small and large service businesses buy advertising in the mobile era,” says Carl Holmquist, founder and CEO of Freespee. 

“In the pilots we have conducted this year, our customers have experienced their first instance of proven and reliable return on mobile advertising spend.  We are now looking forward to making Freespee Ads available to enterprise and business owners throughout Europe.”

A counter on the company website says the company has already connected more than 8m calls from mobile customers.