In many ways Google is on the same playbook as Microsoft's Embrace/Extend strategy, but perhaps in slightly more creative and net positive way.

Google embraced search, and they're basically the only one left.

They embraced email and their free offering distorted the market to enough extent to make most other providers also-rans, except a few key players.

Youtube is the only viable player left in the video sharing field. RSS readers are recovering but it also was a blood bath. I could go on for long, Google coming and leaving(or not) markets has huge negative impacts that I don't see Twitter having in general.

Google's search bubble is arguably more impactful than Twitter's social bubble due to reach, imo.

Google is an ad company, but search is their foremost product, unlike social media.

Ads are their foremost product. Search is just their vehicle for delivering ads to viewers' eyeballs.