I think personal email is far worse, particularly because it is not visible to people who start at the company after the conversation starts.
Mailing lists are pretty good, but generally companies don't have good tools to quickly make impromptu mailing lists.
And I think you're not giving enough attention to the fact that things shared on Google+ can show up in your search results.
If you work at a Zoo, and you search for "python," it'd be great to see relevant links about the animal. If you're a programmer, it'd be great to see relevant links about the programming language.
I mean, meeting someone for lunch doesn't need to be searchable. Mailing lists are searchable at later times. Google search integrates gmail results now.
The mailing list software is a good point-does google sell Google Groups software?
Mailing lists are pretty good, but generally companies don't have good tools to quickly make impromptu mailing lists.
And I think you're not giving enough attention to the fact that things shared on Google+ can show up in your search results.
If you work at a Zoo, and you search for "python," it'd be great to see relevant links about the animal. If you're a programmer, it'd be great to see relevant links about the programming language.