Promoted Likes have always made me nervous on FB. One of the Pages I help manage ran a Like campaign. The page is very niche specific and appeals to people living in a certain area. Even though the campaign was targeted, an abnormal (around half) amount of new Likes came from Bangladesh (not targeted, not even close to a target market). We complained but it didn't help. That was 2 years ago and I've seen similar stories since then. Haven't trusted this sort of campaign since that experience and would advise anyone to stay clear of it. Unless of course you want to get Likes for vanity. In that sense, this campaign will help populate your Page, but expect low quality "fans", which could hurt your reach and engagement levels and screw you over with Edgerank.