Sidebar, since I suspect you were commenting more on consumer email services, but this sort of "moving up the food chain for owning customers and lock-in" has b

Sidebar, since I suspect you were commenting more on consumer email services, but this sort of "moving up the food chain for owning customers and lock-in" has been happening for a while in the ESP (email service provider) space that companies use to manage their customer-facing emails. For a bit now all the big email players have been getting acquired as part of some larger "marketing cloud" that attempts to fully integrate that as the hub for an audience platform that then ties in with other external touchpoints and such. One of the aims seems to be that owning the audience and performance data has inherent lock-in, and thus forced stickiness. Really interesting to see in context of recent BI tool acquisitions.