Skype has begun showing callers on-screen ads while they use the Internet telephone service to make 1:1 Skype-to-Skype audio calls using Skype for Windows. Skype's "Conversations Ads" is the company's latest effort to attract marketers offers them the chance to reach Skype's hundreds of millions of connected users.

Conversation ads are available for marketers to purchase in 55 markets where Skype is available. Users without Skype credit or subscriptions will see the ads during 1:1 Skype-to-Skype audio calls in Skype for Windows.

Skype said that call quality will remain the same. Ads will be silent, non-expanding and run after the software has completed its regular quality checks on each users' connection.

Here's an example of what these new ad units will look like:



Microsoft's Skype Internet telephone service hopes to quadruple the number of users to get to one billion, division president Tony Bates said two weeks ago at the All Things Digital conference in California.