There is a huge difference between just getting more likes on your fanpage and getting targeted likes which convert well on facebook and will ultimately lead to increase in your business.
Facebook has been cracking big time on fake likes which have been taken by some methods like exchange.
Although an initial 200-300 ans on your fanpage can give it an initial push and once you start posting some interesting stuff, it can get viral very easily.
We have often seen how meme and comic images get viral on facebook and there fanpages have millions of fans.
This is something which is possible only due to continuous updates to the fanpage with interesting stuff which others like.