only 231,000,000 results for make money online - not THAT competitive, just moderately. Keep in mind there are lot of other things that could have happened to his site you are unaware of to cause the drop. Also maybe tons of links from the same place, not diversified.
Link baiting is a good idea, but if you link bait to your home page... with the same anchor text... You are gone deep down... A good number of sudden links to a deep page is understood/overlooked by google IMHO..... Also in a link bait, you get lots of links with various Anchor texts. But try anchor texting you link bait like "make Money Online" and you are gone. Too bad if you are linked to your Home page.. Another thing, Link baits works wonders for more established websites/blogs who get a a dozen or so back links each day... For a new site, hmmmm.... be cautious