Last month, we saw Alexa adding huge watermarks to their history traffic graphs.
Now they have included roll-over Adbrite ads [BritePic] on all Alexa graphs that are generated using the Alexa site widgets. And it's against Amazon policies to display Alexa charts without the ads.
Since these new Alexa graphs are done in Adobe Flash, the standard copy-paste techniques won't work but you may still download the Alexa charts of any website(s) in image format from the Alexa Traffic Rankings page.
In related news, Loren Baker discovered that Alexa.com is also selling sponsor boxes in the 125×125 graphic format similar to ones that we commonly see on blogs like TechCrunch and Mashable.