First appeared in Asimov's. Collected in Rudy Rucker's Collected Stories.
Diane hooks up with Jeff and Jeff hooks up to the internet. He makes money through the internet--albeit not enough to support himself--promoting bands, chirping, flooding opinion polls with phony responses. Dubious if not criminal. But he's a sensitive guy, and as much Diane would like to dump, he does things that draw her back to him. When he hooks his brain completely to the internet, it seems to spell doom for the relationship. He's a walking advertisement.
The ending threw me for a loop. I'd expected--was set up for?--one ending and received quite another. I do appreciate the change-up, though. More fun.