Gamigo is telling you to tell your friends to play their games with them. Perfect for social distancing (which should still be called physical distancing to properly reflect what it is, but eh, it’s close enough). On their website, they list their games and each one gives you a code (a generic one) that they can enter into their account to give them a goodie. I tried it out and yes, it applies to us veteran players as well!
Trove gives you the Papa Geio ally (a non-combat pet).
Rift gives you a Stolen Eldritch Steed – you need to apply the code to one of your characters, so choose wisely!
Defiance gives you… “Giveaway Stay Home Voucher”. Very descriptive. It doesn’t list a game, though. I would like to now tell you what I received in the game, but there are only items to claim with no text on why I can claim them or where I got them, but I think these items have probably been in there before. So, I gave it a try with my second account where I’ve never played Defiance 2050 (or Defiance 13). Even after exiting the tutorial, there is nothing at all. In the account management section, I also noticed that for the other two codes, it says what I got and for which game while the code for Defiance 2050 doesn’t list any game. It may be broken…
In other words: There is supposedly something, but I have no idea at all what it is or if it’s working. ArcheAge has no voucher, so there is nothing you can get for that game. Probably because they’re only the publishers.
I am not playing any of their other games, so I didn’t check.