If they’re serious about their monetisation through ads (which they are, and the venture capital funders agree that they are), not for another twenty years at least.
My original answer said “Unless there’s a lot more monetisation going on than we can see”. Well, there was.
When they burn through all their venture capital. Unless there’s a lot more monetisation going on than we can see. Or Jimbo Wales somehow assimilates it into Wikimedia, but I don’t see how that’s gonna happen.
I give it five years.