[taurath]

Google + FB has 85% of the mobile ad market, with margins upwards of 25% of their ENTIRE business, not just the mobile ad market. I'd estimate that their effective margin on just search + ads to be somewhere in the 200-300% range so they can afford to do everything else. The fact that no competitors can get in on margins like THAT, at ANY price, tells you something.

I absolutely believe investors would collectively drop a cool $50 billion if they could become a direct competitor to Google. Why can't they? Not because Google will go after them in a direct way, but network effects are de-facto monopolies, and you'd probably have to spend a $500b dollars and never make money to start making a real dent. Its an impassable moat - the only chance any company has is to have a massive share of whichever platform comes next.

[orky56]

The question becomes, are companies that are successful due to network effects worthy of anti-trust probes? Network effects will always lead to monopolies since the incentive for someone to switch to a new service must have an increasingly larger value proposition over the incumbent.

[taurath]

Yes - ease of competition forming naturally is a frequent reason for anti-trust. Granted, why Comcast still exists is anyone's guess.