example forms which one is better for ranking ? or are they all same? 1. realestate 2. real estate 3. real_estate 4. real-estate thanks,
I'm guessing you are asking in relation to keyword rich folder names or page names in URLs. If so Google prefers hyphens as in real-estate (http://www.google.com/support/webmasters/bin/answer.py?hl=en&answer=76329). Note the 2nd paragraph: As far as domain names, I prefer to run the words together like realestate because it makes it easier to type and shorter. Definitely avoid using spaces and underscores in URLs if at all possible...
I agree with Canonical, I would drop hyphens and underscores in domains but use hyphens in page names of the website.