The smaller ISPs are just following Comcast's example: "You mean we can charge multiple times for the same data without doing any extra work? Sign us up!" All last-mile ISPs will eventually realize they can hold everyone hostage, so long as there is no significant competition.

Small ISPs also like this because they typically are very heavy on paid, private internet and don't do much peering due to having small, localized networks. They stand to gain, proportionally, the most since they can charge the people the were previously paying for access.