[tomjen3]

Unless the logo is extremely bad it won't effect conversation, and it's more important to be able to change parts of the rest of the graphics cheaply for ab testing purposes than devine the result initially (a great design can improve conversation say 15% better than the result from one of those sites, but that can be done with a few an tests).

[stylejam]

I guess you mean conversion and not conversation. A/B testing is part of every sane design process, there's no "divination", only iteration. Knowing the process of design would definitely help here.