It's common enough knowledge that spamming backlinks, along with good onsite optimisation, will get you into the top 10 for just about anything (so long as you spam enough, of course).
It'll also get you banned a few weeks later.
I guess, if your product has a high enough profit margin and you sell enough in a short space of time, then this tactic will still be enough to make a fast buck. To be honest, there's not many industries besides cheap dodgy knockoff manufacturers who's profit margins are high enough to justify this sort of 'slash and burn' technique.
For example, I wouldn't do this for my clients, because I'd quite like to be able to invoice them again in 3 months time.