Forum Moderators: open
What you're seeing is an affiliate link, I believe from Linkshare (someone correct me if I'm wrong). They include the 1x1 GIF as part of the link tracking -- so it's not spyware or anything. Unfortunately, it also causes the browser to hang on occasion ....
<added>On reading your description more closely, it looks like the site owner may not be setting up the affiliate link correctly, causing it to load the 1x1 GIF instead of going to the site it should.