Webmail has always been a loss leader — search or homepage being the main ties.
One of its most money-losing aspects is the multiplatform support. Non-web client apps via IMAP or POP in the old days where people wanted to see their mail in an interface where you can’t serve ads or search.
Those days are back: mobile mail apps.
In the old days there were wars, when you couldn’t get mail via certain protocols. Hotmail still wont let you check mail on a normal PC client. Gmail has always been more open.
But the wars are back too: Gmail doesnt let you sync contacts with Windows 8 or iPhone for that matter. You have to do some goofy stuff.
If Gmail makes a few more moves like this, the door will be open to the next Gmail.