Loss is expected at 60 times per 1000 times = 6000 satoshis. Win is expected 940 times = 940 satoshis. Nett loss every 1x wager = 5060
This is just an expected loss though, it can always go above or below 60 depending on how lucky/unlucky you are during that session. On the wagering part I agree, i've participated in different wagering contests before and if you have the patience to bet low you can go as high as wagering x100 of your bankroll but those are dice sites with 1% house edge. x30 is not that bad considering their house edge is at 5%.
You are right, you really need to make an effort to bet as much as you can to increase your wagered amount but making your bet not so aggressive at the same time, stay discipline as you main purpose here is just to increase your wager overtime to have the opportunity to enjoy the reward once you are lucky.
This promo by the gambling sites is a very popular one, this is to encourage more bettors to play and even if some are lucky enough to win the contest, overall, they are still profitable.