The unforseen challenge is the never ending search for a profitable product. You can do all the research on earth, see a product selling bonkers, and get stuck with a dog, or worse, a hot selling money loser.
No one can predict the market with any real success. All you can do is put a product out there and see how it goes. Every warehouse on earth is about 10 to 20 percent dead inventory. Stuff you can’t give away for free.
People who are new to e-commerce don’t understand this simple truth. You all worry about returns, sales metrics, best place to advertise, sourcing, etc. This is important, but you all have to accept that, odds are, your first several items will be dogs, and yesterday’s hot seller is today’s fidget spinner.