Industries to steer from when starting a new affiliate business

I'm currently in the process of determining a market to plunge into with affiliate marketing, however i'm aware of certain industries that might prove "problematic" due to high competetion and risk.

One of these industries I know of is gambling. Anyone have any ideas about the others?

Pharmacies are quite on the same risk scale with gambling (or at least in my vision).

That seems to be an accurate statement, based on what i'm reading.

I've also heard that markets that have a lot of popularity in sites/searches, consequently make new sites longer to get registered in ranks. This dreaded sandbox i've been hearding about. Is this correlation between popularity and google sandbox time accurate?

Beware of PPC!

Pills, Porn and Casinos.

Not sure the sandbox has anything to do with popularity of search terms.

I would think about your exisitng site if you have one and the types of products your visitors would be interested in. If you don't have a site - focus on what you know about or are passionate about and see if you can find a product that would be a good fit. It's tough to get started, so if you start with a market that has products you can get excited about it willl help you stick with it and make it easier to generate content in the early, no income stages.