Just learn how to target the demographic you are trying to promote. Its not rocket science.. its all about conversions.. so the amount you spend on advertising has to be lower than what you make.. so it all depends on the landing page and the offer you are trying to promote.. thats more important.. Then target it using the ads.. if you make the offer ultra targeted.. bid on impressions, rather than clicks. Example, if your pushing an offer for say sportsbetting.. The ad should be targeted to just people interested in that.. and make something they want to see.. for example the ultimate free betting guide.. then when they get there have method and then link to sign up for betting site etc.. You could also gather uids from pages and groups in that niche and then target only those uids.. since you know all the people are interested, your ctr will be high.. so just remember all about landing page and offer.