I've given likes to businesses I actually liked but I can't say it's made me buy more stuff from them or interacted more with them.
Speaking just for myself and my situation, what keeps me connected to a business are things like opt-in emails, the promise of a discount, a coupon now and then, private sales, announcements of sales. Articles are of interest to me, specifically ones that discuss techniques or seasonal events. I get an email from a company that not includes offers and new product announcements but also videos and articles. It really gets me to engage with their site much how a Brookstone mall store might draw you in to play with their gadgets.
So for me, getting me to their Facebook page is the start, but liking them should not be the end of the transaction or the goal. Getting me to sign up for something that creates a relationship between myself and the vendor is, perhaps, a worthwhile goal. What do you think?
Behavioral targeting on Facebook seems to be well implemented. I recently found a great business through an interest based Facebook ad. I haven't purchased anything yet, but that's because I'm not ready to buy. But I have certainly been tempted.