I never played FarmVille, but some friends did, and FarmVille sent notifications to your friends as well. Only a handful of friends playing FarmVille meant 1-2 daily notifications from that game. Notifications were effectively unusable at that point, until Facebook separated game notifications from other notifications.

After that, it never really got any better, for me at least. Notifications tended to be less relevant than before and I disabled them on all devices.