Grats to you, their VIP level bonus is indeed awesome. Not only highrollers has the chance to get the bonus but almost all players has the same chance to get bonus because it is based on how much we wager on the site.
Obviously it should be a great place for high rollers as the bonus is so huge for them. As we all know there are many high rollers in this bitcoin gambling industry, so I guess it is a good feature to attract those high rollers to stay longer at bitdouble.