5.1 Third Party Advertisements
Some Skype software clients may enable third-party advertisements provided by Microsoft Advertising. In order to provide ads of greater interest to you, these ads may be targeted based on non-personally identifiable Skype profile information (including profile information from linked LiveID accounts), such as age, gender, country of residence, and language preference, as well as other information Microsoft Advertising collects outside the Skype software client. For instance, Microsoft Advertising may utilize the same browser cookies set by Microsoft websites to enhance targeting within the Skype software client.
Except for the modern Skype client running on Windows 8, you may opt-out of Microsoft targeted ads in any Skype software client that enables targeted ads by visiting the privacy menu in the Skype software client toolbar. If you opt-out, you will still receive advertisements based on your country of residence, language preference, and IP address location, but other targeting information will not be used. For the modern Skype client running on Windows 8, you may opt-out of receiving targeted ads from Microsoft Advertising through your browser by visiting http://choice.live.com/advertisementchoice, or the NAI or DAA sites described below. For more information about how Microsoft Advertising collects and uses information, please see the Microsoft Advertising Privacy Supplement.
In some instances, Microsoft Advertising may facilitate the placement of advertisements in Skype software client by other online advertising networks. These companies currently include, but are not limited to: 24/7 Real Media, aCerno,Inc, AdBlade, AdConion, AdFusion, Advertising.com, AppNexus, Bane Media, Brand.net, CasaleMedia, Collective Media, Fox Interactive, Interclick, Millennial, ROI Media, Social Media, SpecificMedia, Tribal Fusion, ValueClick, Yahoo!, YuMe and Zumobi. If you have opted-out of targeted ads in the Skype client as outlined above, Skype will not pass any profile information to such advertising providers with the ad request. However, because these third parties may place cookies on your computer that facilitate their own targeting, the Skype opt-out mechanism described above will not necessarily prevent ad targeting by these companies. These companies may offer you a way to opt-out of ad targeting based on their cookies. You may find more information by clicking on the company names above and following the links to the Web sites of each company. Many of them are also members of the Network Advertising Initiative (NAI) or the Digital Advertising Alliance (DAA), which each provide a simple way to opt-out of ad targeting from participating companies.
Failing that somebody has worked out how to display unsolicited ads through some sort of security hole that exists within Skype. Either way, if you aren't happy with it, uninstall it and use an alternative - that sort of thing makes for good customer feedback.