Enough already
I'm not sure which is more corrupt, inept, incompetent, and useless -- the USPTO or the USgov. It's easy to see the real point of the patent system when you read that the patent "examiners" have to fulfill a monthly quota for granted patents, and also that the USPTO charges what I would consider a rather hefty fee to "re-examine" a patent they never should have granted in the first place. It's a money-making outfit, plain and simple. The fees collected make money for the government, and the patents granted make money for the corporations that can afford to file for patents. The idea behind patents is a noble one -- allow an actual inventor a limited monopoly on their invention so they can recover their R&D costs. Unfortunately, like everything politicians touch, it's been twisted, corrupted, and mangled into something that barely resembles its former self.
Having said that, in the USPTO's and Front Porch's defense, this patent was filed on 3 Nov 1998, long before online advertising became what it is today. That was back when most people were still on dialup, AOL was hugely popular, and a page didn't link to 5000 Javascript files and take up 700KB; before we needed Adblock Plus; before Flash (and the oh-so-wonderful ads, popups, pop-unders, etc. that Flash has given rise to). So the possibilities and usage probably weren't as readily apparent back then as they are today.
As for the incompetence of the USPTO, let's not forget that this *IS* the same patent office which gave a patent for a method of swinging on a swing (patent 6,368,227):
http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=6368227.PN.&OS=PN/6368227&RS=PN/6368227