Yeah Google doesn't get social (you forgot Buzz in your list) but at least they try, and keep trying in different ways, like it different fields, until one sticks (you forgot Chrome in your success list - it doesn't bring money, but it allows them to partly dictate where the web goes and how it works, something that is a lot of value for them). When they get something that looks cool, they try it.
Yahoo didn't even try, when they got something cool, they went "ah, nice" and then closed it or forgot about it.
> EDIT: I use and love Google Photos but I can't remember the last time I heard someone talking about it. Instagram did it with a social spin.
Same, but as the same time, I would wager pretty much every android users uses it, and has more photos on it than on instagram. It seems the value of google photos for google is not to monetize it directly, but as a way to 1. have data to mine, 2. know more about each user to improve their other revenue source and 3. to keep the user tied to his google account and ecosystem. From that point of view, it's a massive success (and it explains why they went that route and pretty much killed picasa instead of the opposite).
In the end almost all of the tech successes and failures listed are reducible to a much simpler explanation: the effectiveness in using network effects to create moats, and defending those moats by adapting to technological change.
Controlling an operating system is a massive such moat, see Microsoft, Google and Apple. As is the first effective search engine - once you have both the eyeballs and the advertising revenue, it's almost impossible for any competitor to displace you.
On the other hand, an email service is not such a thing. Gmail is a good product but it's easy to duplicate or disrupt by other email providers and various messengers. A content hosting platform, be it for pictures, videos, or simple html websites, will not produce strong network effects by itself - this where the "social spin" you talk about becomes essential.
Yahoo persistently failed to create and defend these network effects. Messenger was such a strong network effect-inducing product, but they failed to adapt it to the mobile era and destroyed it through heavy advertising and blatant disregard for the user experience.
Facebook are currently in no such danger, they have a few massively addictive products built on strong network effects. Sure, some people might move to other forms of socialization - but billions more are going online, in countries with rapid economic growth. There is nothing on the horizon that significantly threatens Facebook's moat.
Chrome is and was a fortress intended to defend the approach to their river of gold: advertising. A dominant browser controlled by another technology company is an existential risk to Google as it would provide a point at which their advertising could be entirely disintermediated.
Yahoo didn't even try, when they got something cool, they went "ah, nice" and then closed it or forgot about it.
> EDIT: I use and love Google Photos but I can't remember the last time I heard someone talking about it. Instagram did it with a social spin.
Same, but as the same time, I would wager pretty much every android users uses it, and has more photos on it than on instagram. It seems the value of google photos for google is not to monetize it directly, but as a way to 1. have data to mine, 2. know more about each user to improve their other revenue source and 3. to keep the user tied to his google account and ecosystem. From that point of view, it's a massive success (and it explains why they went that route and pretty much killed picasa instead of the opposite).