An offer is worth what its terms let you keep, and the number in the headline rarely decides that.
That is the first thing to check in any offer, here or anywhere else. Winnings paid as withdrawable cash are worth their face value; winnings paid as bonus funds behind a turnover requirement are worth a fraction of it until the requirement is met. The rest tells you whether the requirement is reachable at all: the stake cap, the expiry window, and the share each game contributes.
Campaigns change, so the operator's promotions page is always the authority on the amounts and dates in force today. The guides below cover how to read an offer, not what happens to be live.