I have found out that it is really important to build up Co-Operations with other companies to drive traffic and content to your site.

In my opinion, Co-operation means giving something and getting sth for it, for example - swapping content, swapping banner advertising. Do you think you need lots of money to build up cooperations ?
Link Exchanges between sites with similar topics selects the right customers to the site.

I tried to get different website owners to build up joints with me, but i guess you need a reputation and money to get them on the line, what do you think ?