Forum Moderators: open
...keywords highlighted on their webpages. When you click on them, it takes you to advertiser site
It sounds like one of the many ways that adware (also called spyware, scumware, parasiteware) works. If so, you will not see this effect on every computer, only those who have installed software to create those links (usually installed unknowingly.) Running a clean-up application like AdAware will find and remove these sneaky programs.
We are not going to give publicity to the companies who create this programming and sell advertising through their vehicles - especially because this is the HTML Forum, and also becuase the great majority of the public consider this form of advertising to be very questionable - hence all the applications available to remove the sneaky stuff.
You can tell the difference because these IntelliTXT pop-ups have a little light gray link on the pop-up div that says "what is this?" - which leads you to the explanation when clicked.
We've got about 60 threads on the forums here about that ad delivery technology - see [webmasterworld.com...] for example. Firefox's Adblock will disable it.