Called "Conversation Ads," the new ads will appear in calling windows of users who are using Skype Audio (not Video) for free -- in other words, who haven't paid for Skype Credit or subscriptions.
From a June 13 post on the official Skype blog:
"While on a 1:1 audio call, users will see content that could spark additional topics of conversation that are relevant to Skype users and highlight unique and local brand experiences. So, you should think of Conversation Ads as a way for Skype to generate fun interactivity between your circle of friends and family and the brands you care about."
The good news for those who don't find targeted ads something that spurs fun conversations among them and their cohorts: Skype for Windows users can opt out of allowing Skype to use at least some of this information. Go to the Privacy menu in Tools and choose "Options" in Skype for Windows.
"If the user opts-out, they will still receive advertisements relevant to their location, but Skype will not use other demographic information for this purpose. To opt-out of the use of non-personally identifiable information by our Ad Serving Partners for the purpose of serving advertisements of greater interest to you please visit Microsoft Advertising at http://choice.live.com/advertisementchoice. Or you can visit the websites of the Network Advertising Initiative or the Digital Advertising Alliance, each of which provides a simple way to opt-out of ad targeting from participating companies."
Microsoft is allowing advertisers to buy ads in 55 markets.
I've never noticed an ad when using Skype audio. But then again, I don't really see ads anymore when doing anything online. I just don't notice them. But the way Skype is planning to present Conversation Ads would make them pretty hard to miss....