Robert_Charlton - 7:17 pm on Dec 3, 2011 (gmt 0)
Inasmuch as I can determine, there's no such thing on Twitter.
"Sponsored themes" apply to WordPress, and Matt Cutts has suggested that they can get you in trouble... [mattcutts.com...] We were just discussing them in a Supporters Google SEO thread here (paid support required for access)...
How to remove thousands of garbage links
From what I can tell, Twitter offers only "Promoted Tweets", and there's a basic twitter help article here...
What are Promoted Tweets?
I don't (yet) see any reference in the article to the self-serve platform.