eBay used to be a homey little site, with (as I can remember) about 20 categories. That was it — just 20. When I started writing about eBay, each year, with each new book, I'd manually count the categories so I could show the growth of the site. Today there are 34 top categories, but the subcategories and the sub-subcategories must be well into the six-figure numbers. eBay has grown to such an incredible marketplace that counting the categories would take much more time than it's worth. Take a look for yourself.
Click the Categories link on the topmost eBay pages (just below the search bar), and you'll come to a page that looks something like Figure 3-1.
Figure 3-1. The first third of the first screen of eBay's sales categories.
See those huge numbers next to the categories? They represent the number of active listings in each category. Also note the link at the bottom of the main category listing; you can click it to see all subcategories in that category.
Speaking of active listings, Figure 3-2 is from Medved.net, showing a graph of the number of auctions hosted on eBay during the month of December 2007. It's a huge amount, at one point exceeding 18 million auctions in one day! You can check this chart on a daily, monthly, or yearly basis from
Figure 3-2. eBay Auction counts from Medved.net.
All of the above ...