As a buyer I use watchcount.com, it's free and no registration needed.
Sorry if you are all familiar with this already, I'm new.

As a buyer, this shows you how many other people are watching the same item you are.
Can come in handy. Depending on bidding and watchers you may actually want to be online at auction end.

In the keywords box you type in the ad#. Use 130783486145 as an example.
It is Fred's ad (tahoe_chips) for the Castaways chip he just advertised.
Hope you don't mind Fred, extra exposure never hurt.
It was showing 19-20 watchers.