In domain names does adding a "-" help with SEO much. For instance someone searched, "adult videos". Site 1: adultvideos.* Site 2: adult-videos.* What do you think would rank higher?
adultvideos would probably be better than adult-videos because all it looks for is the keywords and the closer they are and the less stuff in between usually the better. But won't really make much difference, the key is a well made, structured site with decent, unique page titles, keyword rich content, lots of original content and lots of quality backlinks.
To be brutally honest, while there may be some effect of hyphenated names, any 'authority' weighting and backlinks would make short work of any percieved advantage... Matt (Cutts) has said that hyphens are prefferrred over underscore, but in truth... a ton of quality links and an aged domain... will make it a moot point
i dont think it matters anymore. It used to be good to have something between words a couple of years ago.
There was quite a bit of discussion on this topic here: http://forums.digitalpoint.com/showthread.php?t=252080&highlight=hyphens
Well it sure doesn't help. If you use - or not it is the same thing. However, its easy to remember and most people always type the one without the -