Extending the number of their participant is good indication that their campaign is doing good and they really get nice exposure in this forum that's why they try to maximize their exposure to gather more traffics from people here.
Also yes its undeniable that signature campaign is efficient way to market their casino but it will be effective if they operate a long term campaign and not a short one since we could see that those casino run a short term campaign didn't manage to have a good exposure and fail. That's why if they try to launch a business here they should choose to have long term campaign so that they get more better result.
With several times of their signature campaign expansion - two times as I remember - it is likely Rainbet business has developed well recent months while they also saw good effects from the signature campaign so it is convincing enough for their owner and marketing team to decide a campaign expansion.
Under management of Hhampuz, they surely have been working with a professional manager who is like a guarantee for their success. With his professional, experience and dedication on bring success to his customers, he will be able to provide traffic and effects from the campaign for Rainbet.