Champion Skins Seen Album
The other day I was playing a game and had a teammate lock Poppy. On the loading screen, the champion appeared as "Noxus Poppy" with this sweet looking gothic skin that even in years of playing I've never seen. It hit me: why not give players a mechanic to keep track of skins seen over time? This would add value and significance to old or rare skins.
A great addition to a player page would be a "Skins Seen" album for players to keep track of and view skins they've seen other players use. I don't know how many skins are in existence, let's just say 500 for sake of an example. Players would start at 0/500 and then add skins with each new appearance. Skins seen would be viewable/sortable in the album. This would be different than the shop because skins no longer for sale would be viewable in this album, as long as a player has seen another player use it. Think of them like a trading card, and as long as another player wears the skin then you get the card added to your album.
I don't see how this could be a negative addition in any way (though I'm sure someone else will be able to explain). Instead, this album would promote skin variety and purchases (cough cough Riot here's your incentive) especially for skins that are brought out of the vault each year. It would promote positive player dialogue pregame (Oh you picked Mundo? Do you have Toxic Mundo? Do you have Corporate Mundo? I need X).
From someone who likes to browse champion skins in the shop just because they look cool, I think this would be a great addition that would give players something to work towards and talk about. I don't even mind that it would boost Riot profits - Make it happen!