The Welcome Bonus at Spin Casino is fairly generous at up to $1000. This is definitely towards the upper end for what is possible from welcome bonuses, at least without being disingenuous or having ridiculous terms.
The welcome bonus here is a 100% match based on what the player deposits. The maximum first deposit is $400. This means that you end up with $800. The second deposit bonus is also a 100% match with a max of $300. So, this means the first two give you $700 in free money. Then, you can also do a third deposit that goes up to $300 for the match as well, which is how you get the $1000.
Players have to get all their bonuses in within 7 days of the account opening or it doesn't count anymore. There's also a requirement where you have to play using the currency from the country where you signed up. With the exception of the case where there's no currency for that country offered. In this case, you can do anything you want in terms of choosing the currency. There is also a minimum play requirement before cashing out the bonus.