Ok -

don't try to cheat the system - with trying to earn more impressions by visiting sites for that sole purpose. If you are wanting to view some other sites to see if the exchange is actually working (which I can guarantee it is) then go to the directory of the sites for the traffic exchange and visit a few.
And, as I explained to Linda - if you clicking around on your own site or refreshing the page over and over - the system sees that someone is trying to cheat the system to earn themselves more credits - so it will ONLY show the default ad (which by the way helps everyone IN the system to try to get more members.. that isn't an ad for "us" as in TheMomBlogs.com or Moms Network - that default ad brings them only to the traffic exchange page to join and nothing else.)
Also - remember that there are MANY sites rotating people's ads and not everyone is showing all the same ads at the same time - the rotate and once someones impressions are used up - the default button will show. Let's say that there have been 1000 impressions earned for all the current sites involved....and if the exchange is getting 11,000 views a day... especially because of one or two busy sites - then all that will be left to show is the default banner until more impressions are earned from people. But again.. MANY people signed up and there are still more than 65 that have yet to upload a button to even be able to be part of the exchange. We have been checking their site and emailing people a few times about this, which it taking quite a bit of time.
And PLEASE remember - there are not too many busy sites in the exchange... except for our KidPrintables.com one which gets daily gets 30,000 - 45,000 page views and the button exchange itself is showing 10,000 impressions on that site. Until we get more and more sites in here - people's impressions are used up rather quickly.
So... boils down to.. yes this is working the way it should... and it needs to grow to not have as many default ads showing. And.. be sure not to refresh your pages over and over or even going within your own site/blog over and over on a given day it will see as cheating. You can log into your account at any time to view what your stats are
Also - here are the stats for the entire system - which you can view at any time
http://themomblogs.com/traffic/info.phpThis is a very sophisticated script that works well.