If you're going to buy back links can be risky.
If you own a food website be sure to get food related back links not ones from car dealers, plumbers or like a request we got recently from a swimming pool cleaning service.
We're fortunate that most of our clients are mom and pops and small businesses.
We have to seo mostly to within a 50 mile radius of their businesses. One method we use is consider old and outdated by most of the newer seo dudes now...but it works.
We've found out that many of things that are said that don't work anymore still do work and work better than the new highly taunted ones.
I could really open up a can of worms as far as web design is concerned.