Skype said today that for the first time advertising will appear in the “Home” tab of Skype for Windows starting this week.

The first advertisers on Skype include Groupon, Nokia, Universal Pictures and Visa. Skype said ads would initially appear in the U.S., U.K. And Germany.

Skype “Home” features a sponsored masthead space of 650 x 170 pixels expandable to 650 x 340 pixels for advertisers to show ads that can include audio or video. Advertisers can add a Click & Call button in the ad as another call to action and users can share the ads via their Facebook or Twitter accounts.

More details of Skype advertising come from Doug Bewsher, Chief Marketing Officer for Skype. Bewsher offers the following:

*The ads won’t interrupt your Skype experience. You won’t suddenly see annoying pop-up ads or flashy banner ads in middle of conversations.

*We may use non-personally identifiable demographic data (e.g. location, gender and age) to target ads, which helps ensure that you see relevant ads. For example, if you’re in the US, we don’t want to show you ads for a product that is only available in the UK.

*You can opt out of allowing Skype to share this non-personally identifiable demographic data with advertisers from the Privacy tab in Tools Options.

*You may only see ads occasionally. Our initial plan is to show an ad from one brand per day in each of the markets where advertising is being sold.

*The ads will appear in the Home tab in Skype for Windows, and we may experiment with ads in other areas as well.