My guess is that without advertising, content providers would have to turn to a subscription-based model. I would actually like to see this, because it means a lot of sites would finally die off. Take any website (IGN, Gamespot, Gamefaqs) that does videogame reviews and/or guides. Most of these websites are dinosaurs - they come from a time before the Wiki model and streaming video, when people had to go to them to get reviews. As such, their entire business model is heavily susceptible to corruption - such as the Gamespot reviewer that was fired for giving Kane and Lynch a negative review when the producers of the game had taken out full-page ads for the game on Gamespot.
Nowadays, if I want to find out how to do something in a game or whether a game is worth playing, I can go on Youtube and look it up - usually resulting in better quality than a published guide or review on one of those sites. As an example, last night I wanted to know how to speed-clear this one grinding map in the Vita release of Disgaea 4. There's a guide on Gamefaqs that tells you how to do it in far too many words. I can't quote it word-for-word, but I can come close.
"The best way to clear this map quickly is to use Desco's Yog Sothoth ability (learned at level 100) and fuse her with another monster in order to increase its AOE. Normally, Yog Sothoth's AOE looks like this:
XXX
XXX
XXX
The fused form looks like this:
XXXXX
XXXXX
XXXXX
Where X are squares that her attack hits. The enemies are arranged in a pattern that matches the AOE of Yog Sothoth when fused. Use the Training Center (with Desco as the leader) to give your other party members (particularly Valvatorez and Fenrich) some of the EXP. If you can't get Yog Sothoth to kill in one hit, try using buff spells (such as Braveheart) or the Medic's Let's Go Chachacha ability to give her another turn. Valvatorez's final ability, Tyrant Flughude, can take out one row of enemies while Fenrich's Big Bang (learned at level 500) can be transferred to any other character for 48,000 mana and hits a larger area than Yog Sothoth when used with a Magichanged giant monster. Be sure to throw the EXP +50% Geo Block onto the nearby panel to increase EXP gain."
In the time it took me to read that, I could look up a video on Youtube and see the same thing done in less than thirty seconds and without terrible ASCII art - and without ads plastered all over. The same thing goes for reviews - I can either spend ten minutes paging through ad-ridden pages to find out what some professional reviewer scored it, or I can go on Twitch or Youtube and look for gameplay footage.