WinBeta reports that Microsoft is offering a promotion to Brazilian searchers to make Bing their default search engine and in exchange, they will get $2 of Skype credit to be applied to your Skype account.
When you go to Bing Brazil (clicking this will set your Bing home page to the Brazilian version), the offer at the top of the page will read:
Resgate seus creditos de Skype agora, uma cortesia do Bing.
Redeem your Skype credits now, courtesy of Bing.
If you click “earn here”, you are taken to this page but the credit would only work, if you are within Brazil. So I personally get an error, saying this does not work in my country (which is the US).
WinBeta says the promotion page explains:
Follow these simple steps and you can “earn up to 60 minutes of calls to mobiles and landlines in Skype”. Once a voucher has been issued, it needs to be added to a Skype account by July 31 but the Skype credit will not expire.