SEO Tip #128: Is Comma A Separator In A Title Tag?
Matt Cutts: The only thing that you need to know right now that sticks out and leaps to mind as a bad separator is the underscore. This is because you might have a_b and we treat that like a_b rather than the words a and b. So, spaces, commas, pipes, dashes, all those things are good separators.
So in general I would say try to make a title or a title that looks pretty for users and any one of those characters can act well as separators as well. So whatever you think looks best for users, whatever converts best, any one of those should work just fine as far as the SEO.
About the Author
Andy Johnson has been on the Internet since the its dawn(ie his first computer program was recorded on cassette tape) and his first hard drive cost about as much his current MacBook. His first byline was in 1993 for a local newspaper rag he eventually helmed, and his last “real job” was at a computer start up which ended when it ended. Throughout it all he’s freelanced and blogged. Now he is mesmerized by Search Engine Optimization forever trying to “rise to the top” for the right reasons. He’s been married to his wife Julia for as long as he can remember and has two lovely, wonderful children. He looks forward to sharing the latest in the technical best for all the online entrepreneurs.