During my days as a drop shipper, I learned that building a web store, or listing on Amazon and eBay is just the beginning to success. Essentially, as a drop shipper, you are a marketer. Everything you do online is to drive traffic to your store.
Spending money on advertising is the easiest way to drive traffic. "rjennett89" says spending $400 is a lot of money. He is right. Especially when you aren't making sales or profit. I suggest you spend your advertising dollars on high dollar profit items. Don't pay for advertising on an item that will earn you a net profit of under $50.
As a drop shipper, you need to realize that you are essentially marketers. Selling exclusively on eBay or Amazon could be a race to the bottom. Everybody undercutting each other to make a sale. Instead, market on social media, article write with links to your site and come up with creative ways to drive traffic to your site. Give people a reason to visit your site. Understand and implement SEO and SEM techniques.
Once you realize that your job is really marketing, you will have more sales. That's why you earn a profit on product that you sell, but never actually own. You have to SELL it!
I say this from experience. I drop shipped for 5+ years through four different websites. Never sold on eBay or Amazon, and made enough money that I was able to become a manufacturer.
Don't worry guys, it's not going to happen over night, but it will happen if you keep at it.
Hope this helps.