Every year, we know it's coming, and yet there's always a moment of palpable, server-crushing excitement when it arrives. And so it has, once again: The 2017 Steam Summer Sale is now underway, and runs from June 22 to July 5.
This year's sale features a "Summer Sale Stickers" quest, to earn "stickers for your Summer Sale Sticker book." Full details are here, but it sounds like they're basically Steam trading cards: Each quest, like exploring your discovery queue or viewing your Friend Activity page, will earn you a pack of three random stickers. Slap 'em in your book, and once you've got them all, craft the 2017 Summer Sale badge, which will also get you a tradeable emoticon and profile background.
Do note that, unlike Steam cards, stickers and sticker packs can only be earned through the Summer Sale quests—you can't buy them or trade them. But missed quests can be completed at any point during the sale.
As for the deals, here are a few sweet choices to get you started: