Consider Google. They acquired Youtube, Android... Google's skillset was perfect for taking these proving concepts and making them 1080px, so to speak. Now, Youtube and android feed users & data to the adwords cash machine. Youtube and android defend the adwords castle, denying competitors. Fantastic synergy.
OTOH, no company will ever find a synergy with ebay. They have spiky bits where companies are supposed to have copulation bits.
[1] https://arstechnica.com/gadgets/2015/04/cheaper-bandwidth-or...
Also, "just give it as much resources as it needs, we're rich" was a game google had already proved willing to win with gmail.
It's easy to lay the tactic out in retrospect. Fund "resource hogs" that users don't pay for. Bet on long term bandwidth costs going down. Bet on major consumer monopolies being valuable, long term. Sounds great and it was great.
OTOH, lets pour $mns into a "business" that we bought for $bns, that has no revenue... because in 15 years we will be worth $trns and it will all sound like peanuts... this was once considered imprudent business planning. Google were willing to do it. Others weren't. Only a few even could.
