* Buzz
* Code Search
* University resarch program for google search.
* Jaiku
* Dodgeball
That services either acquired or created by Google. They were valuable but now closed . For example : Buzz has fascinating technology behing it, but still failed. Google didn't understand users ( there was not so much people because of the invitation thing and mass was important ), user wasn't able to understand "What the heck is the Google Buzz" ( communication error by google ? ).
As for G+, Eric Schmidt's response wasn't the nicest response to give the users who complains about real name policy. And again "elite g+ club" enthusiasm was a mistake, like buzz, because a social network means nothing without your friends ( this time they realised their mistake and act before it's too late ).
And then clueful users didn't want their words used for ads, so they started x-no-archiving their posts. And then eternal September really took off with vast numbers of people using Google Groups.
Usenet was dying a slow horrible death and there are lots of reasons for that (Dutch dumpers; stealth binaries; rushed "standards" like Yenc; etc) but Google didn't help (and probably made things a lot worse) when they borked DejaNews.