I honestly don't think that the number of people using this service (if it happens) will be as great as people are thinking. I'm sure there will be some but if there are ever more than 1000 concurrent users i'd be very suprised.
Its all about the marketing - Tor is a massive pain to use, need a totally new browser, is slow, times-out.....once it catches on about DarkTor, people will leave Tor in droves for a premium service.
Especially when you can pay with Darkcoin and your entry and exit is still totally anonymous.
Its fucking genius
Im excited for things to come. It IS absolutely genius. who wouldn't pay 50 cents or so for 24 hours access. Journalists will use it for sure everyday. Stock brokers.. anyone who doesn't want their stuff being seen. Absolutely brilliant.