If your database keeps growing, you'll eventually exceed the write capacity of a single server, and have to write to more than one place. You're correct that m

If your database keeps growing, you'll eventually exceed the write capacity of a single server, and have to write to more than one place. You're correct that most of the NoSQL hype was cargo-culting, but I don't think it came solely from Google trying to serve ads quicker, I think it also came from companies having too much data to scale vertically.