I play "Legacy of Heroes" as a free player. Recently the game has started offering rewards for playing drafts during Monday afternoon and evening. I promptly adjusted my play to never play a draft anytime other than then.
A LoH draft is sort of like a sealed-deck Magic tournament. You must pay for decks of cards using the two in-game currencies. One of the types of deck is "drafted" by passing it among the four players to select one card at a time. This type is, of course, paid for with the "high-value" currency. A free player can afford to draft about once every three weeks (slightly more often due to special promotions, free decks, coins earned by leveling up, etc.)
So how does this promotion benefits the publisher? Does it encourage more drafts--- if so, how? If anything it seems like it may discourage drafting other days of the week. But, the reward is given only for the first draft played on Monday.
I think the benefits may be:
(1) Slightly increase the amount of coins spent on draft packs, since they are now somewhat more valuable. This could lead to marginal increments on coins purchased (for real money.)
(2) Decrease wait times for drafts during a particular period!
I suspect the second one dominates. Often there is not a queue of people waiting for a draft--- it may take several minutes for one to start. By offering an incentive to draft during a particular window, the whales will have more opponents, and can play more drafts per week, and thus buy more cards. And that drives the publisher's revenue.
(At the same time, the developers have stated they will begin rotating the draft rewards--- which again is aimed at real-money players who have already exhausted what is currently available. But as a free-play grinder it could be kind of annoying.)