The Gist:
Basically, you can't hack the system. But you can build your way up organically.
What do I mean by "Hack the system?" Look at the image to the left. It's a screen-shot from a tool I use that shows me the number of citations/backlinks to a page.
See, before the Panda/Penguin updates, backlinks were how you showed your authority, and anyone who could generate a ton of links to their page won. More and more "black hat" (scammy and fake) methods of generating hundreds to thousands of back links rose up, and many took advantage.
Can you guess which Chiropractor in this page did? The one with 117 citations, or the one with just shy of a half a million...
Yeah. When you see it from this side, it sure looks fake, doesn't it.
It did to Google to, so they fixed it.
If you want real, lasting "SEO", then you need a company which can deliver.