Buyback token is a marketing technique plus at the same time it helps in increasing the demand for the token and also it shows that the company care about its token and they are not interested to dump it on people. However, the initial thing to note is the use of the token and since RLB has the gambling site as a perfect use case, investment in this token can be a good one.
Anyways if you had held the RLB for another year, you might have got them sold at a good price. Bitcoin bull run and Altcoins season will make every coin pump again.
It is not just marketing technique but also a price increasing reason as well, when you buy it back and take it off the market that means liquidity drops and there are less tokens available, which decreases the supply, if the demand stays the same that increases the price.
I believe that when Rollbit does that, it does increase the price each time they do it and that is a good thing for the future of the token as well. Of course it is a casino token after all and there is a stigma about casino tokens so it is not going to be easy to increase it all the time, it is going to take some time to increase it but I believe that it will happen one way or another. We just need sometime, because after some more buybacks it may increase a lot.