Why doesn't Riot give you a special gift or sale for your birthday or anniversary of play?

Wouldn't it be nice? you sign in for a game of league and what pops up is "Happy Birthday Summoner! For your special day have a random skin chest/(or better yet) a skin of your choice!". Or When you sign in "Summoner, Thank you for your dedication to playing League of Legends for x years! Have this reward!" I think it would show that riot really cares about their playerbase, and one skin or some ip boosts or some rp wouldn't hurt a company that makes like a billion dollars a year(exaggeration of course). If not that, at least something like the sales where they give you like 8 discounted skins.