Yeah, re-directing people to your webpage with ads is obnoxious, but understandable, but listing a chapter as available and then showing a "Sike! Only if you pay me first!" page is pretty shitty.
It's much closer to a gangster racket, ransom behavior, or a third rate upsales tactic then anything else. I'm strongly debating blacklisting this group outright. I don't want to deal with this kind of crud when I'm only here for a relaxing read.