In Brazil, during the 80s there was a service called "telegame". A user could use an Atari 2600 cartridge connected to a modem to download games from a catalogue of 150 diferente games.
I bet that worked pretty well considering an Atari 2600 cart is 4kb. Even over a 300 baud modem with all of the encoding overhead that's about 20 seconds to download the whole thing.