[glen]

I think quality is better than quantity. Build relationships with folks you are targeting. Take them out to lunch. I know in-person meetings are not something most of us love to do, but they are really important -- especially for the potential user. Get a handful of say 5-10 people that you really want to reach. Listen to them. Solve their problems. Ask them for blurbs. Put the blurbs on your site. Ask them for referrals etc.

This might not be answering your question, but the hundreds of emails approach (at least to me) doesn't seem like the most efficient strategy.