A promotion is worth exactly what its terms allow you to keep, and the headline number is rarely the part that decides it.
That is the first thing to check in any offer, here or anywhere else. Winnings you can withdraw straight away are worth what they say; winnings paid as bonus funds behind a turnover requirement are worth a fraction of it until the requirement is met. Everything else decides how realistic meeting the terms is at all: the minimum odds, 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 explain how an offer is read, not what is running right now.