These kinds of promos are, of course, subject to great variance, given the time constriant of only 24 hours. The suited Ace-king accours once every 337 hands. So you decide how long it will take you to play that. Then, of course, in that period, you may hit once or more than once, or you may not hit at all. So, there's a great deal of luck involved.
Finally, as you state, if your average blackjack bet is going to be MORE than $100, then the 0.74% is reduced, because, you can't get the bonus payout on anything over $100.
Don