Twitch drops

What are these? This website just had me register

Random chance at free packs when you're watching certain streams when available.

Last night I got 2, two nights ago 3, three nights ago zero. Usually find these available on M-F evening streams, the channel will says "drops enabled" when you go into the stream under the MLB the show game line

And dont do what the thirsties do and type random things in the chats where these happen. The drops pop up on screen, there is no secret code to get them, its completely random.