Really really good idea to attack something like this as early as possible...<p>In the spirit of failing early, this is a great way to figure out where people really what what you think they do. If you can't get a few thousand email addresses, you quite likely have a bad idea or haven't figured out how to talk about it yet.
The phone numbers are a particularly interesting idea, but how did you intend/did you get in touch with all the people after launch? Did you and a few others manually sit around and call 20,000 people?
in case anyone was curious i started doing this and more 9 months before the techcrunch40 competition. i would say 4 months is a good headway to get this going. i think<p>a) some sites dont need outreach or trust to be built since their initial users could theoretically spread the product<p>b)you want to build the relationships and things earlier than you need them.
I like #2.<p>Solve a problem and find the people to whom that solution is most valuable. Start there, cater to them, make them passionate, and voila: there's your base!