You can find an overview of signature campaigns here: https://bitcointalk.org/index.php?topic=615953.0

There are a lot of sites that advertise through the forum and have fairly good relationships with it (ie having support threads and multiple representatives to answer queries). If you've exhausted searching for a reputable casino in search engines it might be a good place to start.

Make sure you do good research before picking one though (1xbit is a scam and there may be others - especially newer ones) but most of these don't have support and discussion threads on the forum too so that might be one good way of determining if they're reputable or not (as well as checking their trust list) and that a site with one of those threads doesn't have a self moderated warning just above the op.