People forget just how good gmail was. It wasn't just a geek status thing, although getting into the beta certainly helped, it was more that every other option was absolutely inodiated with spam, and, worse still, most had very poor tooling available for managing email in general.
Back in the dark ages when I was using Yahoo, I was receiving plenty of email, and about 80% of it was spam, switched to gmail and never had that problem again.
It was, honestly, quite an undertaking to de-google myself, because I'd been at it so long.
Gmail's #1 selling point, as I remember it, was a much more generous amount of storage, for free. I think Hotmail had like 20MB of free email storage, Gmail had one gigabyte.
True, storage was also a thing, I remember using some hacked together GmailFS program, where you could split a large file among a bunch of email attachments that were sent to yourself and tagged, then you could download and reassemble those files anywhere.
I used it to store FLV music videos I found, it was... the okayest form of cloud storage.
I think it depends a lot on usage, I have a "real email" and consider my gmail address as "disposable", I use it to sign up for websites etc, whenever a form ask me to include an email address I will use my gmail address - the only time I ever log in to it is when I need to reset a password or similar.
Yes, that's a big one. Google searches are no longer anonymous now because people are mostly in a logged-in state on their browser thanks to Gmail or YouTube.
