I would buy them all if I could..
If Facebook Search even remotely takes off then that will siphon away a significant amount of advertising that Google relies on. And Google has shown a worrying inability to monetize any of their recent projects. Docs/Gmail/Youtube/Android aren't making much money, Glasses is niche, none of the OEMs are interested in their self driving car technology and their Motorola acquisition has been an unquestionable disaster.
They still rely far too heavily on their existing Google Search/Google Adsense cash cows.
Google funnels most of their diverse online product set back into the primary money generator. I'm sure we'll see less of that in the future as there are so many people that have pointed this out it's almost tiring.