Hmmm...why would they give better retention to web users than NNTP? That sucks. It's as if they have two different services, rather than one. I just don't understand how they work that (or why). I've tried usenet/web combo and didn't care for it. Can you use their free trial in Agent?
Another reason I hate web/usenet is that nasty web code, banners, etc. (things you don't want from spammers) gets launched in a web browser that just sits idle in a news agent.