Forum Moderators: buckworks
The US is fairly overcrowded unless you can carve yourself a very specific niche and find a distributor or dropshipper in that niche.
In my part of the world, we've done pretty ok with putting together brand names, given that there arent many people doing the brands that we carry, online.
A short approach would be:
1) Research a niche and find a product set
2) Find out how its being sold online, ebay / amazon / other major players in that area
3) Figure out the costs ... online store, inventory, advertising, shipping, customer service.
Repeat until you're happy you have something to work with.
Keep in mind that inventory and marketing costs are usually online / startup business killers. The rest can be minimized by doing it yourself.
Lesson #2: Always deal with distributers. Verify with the manufactuer, that they are a bonafide distributer, not a middleman trying to rip you off.