Achieving this sort of bost on Facebook is difficult but can be done. Effectively targeting with ads to reach thousands of people is easy, as you say. However, the trouble is getting the thousands of people to click on your ad and like the page.
Auto liking is a nice way to ramp up your page. However, it can be expensive. In addition, Facebook could get wise to the operation and restrict your account.
The best way is to grow naturally through targeted marketing. I wrote a book called More Facebook Everything that shows people how to do exactly that.
Thank you,
Spencer Coffman