While dropshipping may not make you millions it is a viable source of starting an ecommerce store with little to no money out of pocket.
Dropshipping means you will find a supplier with a data feed, use a platform such as channelape to import those products on an automated schedule to populate your store. Once your store in in sync with your supplier, you can start selling. When you sell an item then you route that order back to your supplier or dropshipper for fulfillment. Sounds easy right, well ChannelApe makes that part easy.
The hard part is differentiating your site from the thousands of others selling the same items for low margins, that is a challenge. Blogs, social media, content, that is what can drive traffic to your site and generate revenue.
I tell customers to use dropshipping to find products that actual sell and then try to negotiate a better deal on those few items and then fulfill them yourself to make a bit more money.
Here is a great guide for more info on dropshipping and other methods of selling online.