I still haven't quite understood how Anki can apparently be profitable when the web sync with Ankiweb apparently supports an unlimited amount of data (surely some people heavily abuse this - but one never hears about fair use being applied?). Even legit and honest use can mean massive collection sizes since you can have any rich media in an Anki collection.
A few things. Up until now Anki was not a business and was not meant to be profitable.
AnkiWeb also does not support an unlimited amount of data. It's evident that their storage requirements aren't infinite. They aggressively cull content. Not syncing for 6 months results in automatic deletion last I checked.
I would still expect ingress and egress costs to be significant - as well as storage for content that isn't culled. And while it was not 'meant to be profitable' my point is that it was profitable, apparently exclusively from revenue from the iOS app which I still find surprising that it would cover the Ankiweb costs.