I am torn between x123keyword.net or x123-keyword.com. Will either have any effect on the domain's SEO potency? The x123 has nothing to do with the keyword, rather something like a company name. And this is in a fairly professional niche (think doctors, lawyers) where a .com domain may help with a customer's perception of the company... But I do not want to be penalized for using a hyphen. What do you all think?