I found that, too many websites, especially in English language sites, they register their domain with "-" in the name.
a simple example, domainname, and domain-name, which one is better and easy to be sold?
the "-" is the alternative to 2 word domain name. Usually when the website owner has the "-" it means his or her...... 2 word domain was taken so the only option left was to register the domain with "-" ....the hyphen
Names with "-" (Hypens) are not prized names to own no matter what the words are, only few really do hold value but usually is because of the site content, and they name ranks better than say a different combo of words. The "-" kills the value of name. Also if you have a domain with "-" and its developed, you could be sending alot of traffic to your competitors site if he or she owns same name without "-" . Thus stay away from "-"unless absolutley need to develop to get to rank better, or is exact keywords you need. Bottom line just stay away from "-" domains .