If someone wanted to develop his own physical product for further distribution - what would be the top 3 products you would recommend. Not necessary specific, but maybe the top 3 niches.
If we're talking nutra, I'd say something in the nootropics or "brain drug" field. I think it is still pretty untapped with a lot of potential. Lot less competition than diet/muscle/skin as well.
Outside of supplements, I see a potential growing market for "accessories" for smart-phones, but beyond the typical cases/car chargers/etc. Tools that can piggyback on the processing power of these phones, (think like the credit-card swipe dongles for Square/e-card readers), but consumer-focused. I saw one the other day, a "breath alcohol tester" that plugs into the top of an iPhone, and gives someone a BAC reading, before they drive. I think there are a lot of untapped ideas like this for consumer-based attachments to phones. I've seen one that reads car error codes, ones that measure speed like a radar gun, etc. I'm sure there are hundreds of good ideas for small plug-in modules for phones that do all sorts of things you can't do with just a software app alone, so can sell a hardware+software/app solution.
always interesting to read about other ppl` expirience and success. are you still a publisher or did you go further? who do you plan to pass your business to?