Would you like to subscribe on hundreds of websites to access their paywall?
The WWW got popular because it's friction-free and many sites are paid by advertisement money. At the moment many ad networks are just stubborn (bad ads) and greedy taking big chunk of the ads money away, instead of sending it to the website owner who is doing the majority of work. So there is definitely a place for a new ad network that disrupt the Web ads that don't suck and with a smaller cut so that the website owner get again a bit more money.