Buying Facebook likes is a fairly common practice for both business and personal accounts.
For one thing, Facebook likes is not only an expression of your affinity, but also of your popularity and your importance. These Facebook likes show others how likeable you are. It's something to be proud of, isn't it?
For another, there are millions of people using Facebook every day. Getting more likes means more possibility to get exposed. You are not buying Facebook likes, but also bringing more traffic to your profile.
At least, getting a bunch of Facebook followers and likes does give you a great sense of accomplishment and satisfaction, doesn't it?