Here are some suggestions to look into (not ebooks in these niches and not how to make money in these niches, I am talking about the legit vertical):
2. Dating Memberships
3. Credit Reports
5. PPI, downloadables (ie toolbars, games, etc)
& Many many more
You can find offers and what networks have the offers you like at oDigger.com and offervault.com
#1-5 I have experience with, there is lots of great opportunities out there. #6 is slowly becoming legal again in the US so it will be a huge growth opportunity in the near future.
So why are info product offers oversaturated? Because the cost of entry is extremely low. Anyone can write an ebook about anything and post it up on a wordpress site if they want. Not anyone can just throw up a Credit Report offer or a Game Download offer without a large cash investment.
So why is promoting info products oversaturated? Because all these info product owners are out here trying to get affiliates because info products do not naturally draw affiliates so they need to pitch their offers like its your only shot at success.
Did you know that many non info product affiliates do not build relationships with their email list at all? They just spray and pray and make 5 figures per drop. If you have an email list in the info product arena, you might not even believe that, but its true! Info products are actually pretty tough sells, so congrats to everyone out there who is profitable doing it. I mean it, serious props!
Why are info products tough sells? Think about it, ebooks are intangible and mostly pretty expensive, you could drop the same cash and get a nice watch or something physical shipped to you. A month later, an ebook is read and forgotten by most people (most take no action) but the watch is still there. So now when the bank statement is checked, the info product triggers buyer remorse because it wasn't a natural response to buy the product, it needed some serious convincing, this is the problem with all virtual products.
To conclude: I don't hate info products, and I don't think there isn't money in building or promoting them. I do think new IMers are missing out on ALOT by not seeing what else is out there before they drink the info product kool aid, so before you choose to promote the latest xyz info product, at least take a look at non info product offers. You may find exactly what you were looking for!