There is a lot to say about this, depending on your product and your market (which I haven't seen). Here are a couple key thoughts:

* Adwords are great, but spending money before you know what kind of conversion you are able to get from natural SEO isn't a good idea. You can always buy traffic, make sure you have the right funnel first - image it is a pipe you are trying to make as wide and friction-free as possible. I think Adwords works great if you are selling a product similar to something already in the market

* forums, blogs, etc. have a very short lifespan so you should expect you will get peaks from high buzz items (like a post doing well here on HN) and it will trail off after that, if you can retain 5-10% that's great. You have to consistently crank out new relevant content.