Live within their means, or it will cost you $25 (because of "revocation costs").
StartCom are pretty awesome, but be aware of potential pitfalls.
To quote them:
"Class 1 certificates aren't revoked free because we receive too many requests daily (specially for the Class 1 free certs) and would we have revoked them all, our certificate revocation list (CRL) would have been blown out of every proportion."
In a further back-and-forth, the admin proceeded to tell me how much bandwidth I would cause them (I don't even care about being added to a CRL for a personal domain).
Edit: Sorry, you did say a wildcard cert, which sounds like a paid cert, so would offer more "service" I'm guessing.
1 - Not an NSA joke, more that "hey, voter registration and property tax rolls are public and online; you could just verify that, no?"