do what I done to my boards so that I got over 1920000 posts in few months only
have many affiliates with other boards
give away Gmail invitations( I sent around 200 when Gmail was rare)
make contests like best poster contest like go into boards similar to NP and tell them I will give u 1000 posts if u make 300 posts at my boards
make ur boards main page look active make some SPAM threads so that it make the boards look active ( this is a bad idea but makes people register) make sure u hid the spam from the places member or guests can see like sub boards [if u need more tips or help concerning that PM me I will help more telling me what is ur boards software)
give away stuff like T-shirts or so in low prices or even free
search engines a good idea I get many daily people from search engines but these people 99.99% view boards but don't make posts
if u don't have much posts hid boards statistics
never and ever be strict to ur members because people need a nice place to post in not a place for u to make them rules(personaly I removed the rules section I just warn members and guests and I never had to punish people at all )
be kind and welcome members and guests , make them feel welcome and they r important up to a limit
never show them that u really need there posts
make a support board
make weird topics which are not very comment so that search engines catch ur site in first pages as comment topics such as health computing ..... got loads of sites with high ranking which will hide ur site
don't put ads at the beginning at all
if u want more tricks contact me to show u how a great forum I have that got pop just in few simple steps