Whether you want your forums filled with quality posts, or you want to advertise on other forums, the best way to go is to get a Web content writing service.  Here are some things that you might want to check if you're going to get value for your money:

1. Good grammar and English skills.  This is often overlooked.  Some forum owners just want to get some activity on their forums that it doesn't matter if the posts come off like some kindergarten student wrote it.  You must build a professional and trustworthy image for your forum, you cannot do that when the posts people see are riddled with wrong grammatical constructions and misspelled words.

2. Ask for a sample forum, or at least "audition" them.  Most content writers, in order to protect their clients, will not tell you the URL of the forums they wrote in.  You can ask for an audition.  Instead of paying big money for a 1000-post package, ask to have 50 or 20 postings at first.  You can probably pay $5 or $30 dollars for that.  If you don't like their work, then no strings attached.

3. Do the posts seem natural?  There are forum posting services out there that are out to make a quick buck.  Can you imagine a forum with a little more than 100 posts and 70 of which comes from the same user?  Or posts that look rather "fake"?  Remember that forums are supposed to be about building a community and fostering conversations. 

4. Are they professional?  Make sure you work only with professional content writers.  This lessens the headaches you'd have.  Responsive and fast service is the key to know your service provider's professionalism... if they take more than a month to answer your initial inquiry, move on.  Can you imagine how much longer it would take for them to reply if you have to follow up on something?

Really great tips

Thanks