[ridgewell]

>2. Tactically/strategically reselling keys legitimately acquired cheaper (giveaways, review keys, differentiated pricing between markets)

Key reselling from giveaways could be mitigated if we somehow figured out a way to make keys expire shortly after the giveaway period (ie, keys expire 5 days after the giveaway ends).

I'm not aware if Steam or other marketplaces have this functionality yet.

[wolco]

a simple datestamp? Not sure I've seen coupons without this functionality why would keys be different?

[ridgewell]

I would be surprised why game developers and publishers don't cancel out old keys from free giveaways to prevent hoarding and reselling then.

[nearbuy]

Steam has a page that lets developers query whether a key has been redeemed, but it only lets you query one key at a time. This makes it a pain to discover unredeemed keys. You also have no way of knowing if an unredeemed key is held by a legitimate potential player or someone trying to hoard and resell.