Heard of zwebtech.com ??

Is anyone familiar with zwebtech.com ?
I received an email from them, I'm sure via
an automated process. They're basically trying
to sell their service of looking at your site and
helping with search engine position, etc..

My questions are...

First how did they find my web site ? I have 2 main
sites available from the net right now, one is live and
real the other is almost identical since I use it for development
purposes. They found my development site but not
my main real live site... hmmm what am I doing
right or wrong for their search engine to find the development
site and not the live site. Anyone know ?

Second I hesitate to respond to them, but wouldn't mind
doing something if reasonably priced (AKA cheap ) to
help generate more real sales traffic.

Comments anyone ???

Jon