For List Building Services see : Leads 2U

To build a list your need to capture people that are interested in your niche:

An example is this system of getting co-reg leads :

Triple Your List is a new innovative marketing
system, which actually generated real-time email
leads for you... ABSOLUTELY FREE!

It is designed to add fresh, targeted, verified
leads to your list. All the leads generated will have
gone through a double opt-in process, so you know
that these are do-ers, not lookers who never take action
on promotions.

Better yet, this is not a mailing system or a safelist.
These leads will actually be emailed to you (free of
charge) as members come into the system!

http://www.tripleyourlist.com