It is because it is the first step in verification. There are three roadblocks.
1st is 10 items sold. 10 days or a year, it doesn't matter. Expect to be called to verify your information. Better have your shit straight, don't mutter, don't stumble and say something that contradicts something else you have said.
2nd is between 50 and 100 items LISTED. They will put a hold on your account if you don't have a lot of feedback. eBay probably isn't aware that not everyone will leave feedback. Now they will verify your identity again, and ask you questions about where you got your items, and get an understanding of who you are and if you plan on selling certain items or just a little bit of this and that.
3rd is your 90 day mark providing you have sold over 100 items, which shows eBay you aren't a small seller and you actually have a good amount of inventory. This is the actual verification of your business. They will review your account and determine if they Want you to sell on eBay. They determine your main categories, and if you sell stuff like iPods, don't expect to get past this as they have a predetermined amount of people they want to be considered as their main sellers in specific categories. If you look at my last couple of posts I mention that a lot of my competitors just disappeared off of eBay, and I believe this is why. I am an American seller that was competing with Chinese sellers but I offered Free Shipping, quickly built a lot of feedback, took good pictures, and wrote proper descriptions and I bent over backwards when someone had a dispute of any kind. Now items in one of my categories that I was competing to sell for $4.00 + Free Shipping, I'm now selling consecutively for $12.00 + Free Shipping.