Amazon is also the number one retailer on the internet. They do over $100 billion a year in sales. People shop at Amazon because it's convenient. But on the other hand, sometimes you go to Amazon to buy something like a printer, and it takes you three and a half hours to figure out which printer you should buy, because there are 387 options in your price range, and when you browse through the reviews, every printer has some reviews that are all like, "If I could give this printer 0 stars, I would. You better not buy this piece of garbage printer. If you do, I'll come to your house and kick your ass."
People also shop at Amazon because most of the prices are good. On the other hand, a lot of the items that cost $3.99 to $8.99 at Amazon can also be found at your local 99 Cent Store. And guess how much those items cost at the 99 Cent Store? 99 Cents. And sometimes you can find the same item on eBay for about the same price, postpaid. Which is very confusing. If you want an HDMI cable, you can buy one on Amazon for $6, you can buy one at the 99 Cent Store for 99 cents, and there's some dude on eBay who will send you eight of them from Taiwan for $1.33 total. How is the eBay guy not losing money on that deal?