Beyond the 100 free points (useful for keeping your account active, if nothing else, you also can win one of the giveaways of additional miles as the promo realizes milestones in the number of participants. The number of miles awarded for each draw will also adjust, up to 100K points. Full rules here as it really isn’t worth trying to explain it more.
Not a bad promo for a couple seconds worth of clicking. Just make sure you set the promo to show timeline posts to only you rather than everyone if you are into that sort of thing.