I find that eBay is a great place to find hot niches simply by finding out what are the hot items that are selling well. There are a few tools that make that job easier, but one of them would have to be straight from the horses mouth – The eBay Market Research Tool.
According to their page:

There are 3 types of user levels for this tool.

From an Internet Marketers standpoint, it is very useful to get access to some very useful data in order to plan what kind of products or niches that are worth considering. Not so much to do trading on eBay, but rather to get insight into the trends, the statistics, and the hot niches.
In addition:
A fast way to find out if the “junk” in your house is actually worth selling, just type in the name of the stuff that you want to sell, and see what actually comes up. You might just find out that there are auctions for that “piece of junk” selling for $50-100. But it’s important to also take a look at the final bid prices (if anyone actually bidded). There are many things that don’t sell too well; and again, there are things that do.
Which means?
Go straight to the closed auctions, and take a look at the final bid prices. Since most bidding occurs only in the final few minutes of an auction, the best way to get an overview is to study the closed auctions. Some products may get listed a lot but hardly sell, whereas others are listed here and there, but sell like hotcakes. These are the hot niches.
A final word – As with all things, trends change; so what may be hot today, could change in a few months or years, depending on the niche. Just something to bear in mind.

