No harm in terms of penalization from the search engines, but if you have too many it may scare off potential visitors from clicking on your link.
no you will see them becoming more and more popular in the very near future - I own a total of 3000 domains and I have now started stocking up on domains with the dash in them because they have begun selling for good money for example I own Kit-chen.com and eMon-y.com I hope it helps (EDITED) Hey Iowa Dog ... You following me around ..lol
I don't think there is any harm from an SEO point of view But I have two domains with very similar names one with a hypen, I registered the second non-hyphenated when I got fed up of saying "just look at onehypentwo.com" and you wouldn't believe the number of people who asked how do you spell hyphen?
having dash in your url doesn't have a negative effect; in fact you you have keywords in the ulr separated by dashes then each keyword is counted as separate word and it really benefits.
Having dash in your url between keywords is seo friendly. But using symbols like _ is not a seo friendly.
There is no harm in using dashes in the URL.Try to incorporate your targeted keyword in the URL and separate it by "-" or "--".The total character of the URL must not exceed 63.
I've heard that by using dashes in your URL the search engines interpret this as two seperate keywords. So if someone is searching using the keywords "hot dog" and your domain name is something like hot-dog.com then it will get a better placement in the search results. Not sure if this is true or not, just something I read. Thought I would pass it around. If I'm wrong please let me know.