We still benefited from those 6 weeks of his bankroll (helped spread our losses)!
Definitely got a help from his investment, doesn't matter how big or small, a help is a help. When you go for years, you are lowering the variance, the difference between 6 weeks and 6 years is the fact that 6 years has a bigger income potential and even a whale can't lose that much. So, let's assume monthly you could make 0.5% of your profit, and you reinvest your initial money back or something, can't really make a big math calculation for it so just hear me out with bad math

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^ Definitely right, the fact that you will not instantly earn a big percent amount in just a couple of weeks. Probably it takes years before you will have a good result and there should not have a variance of your investment that the most you worried about. I saw a thread on the gambling discussion board about their investment in Bustadice and Yolodice but as what I saw there it seems all went good. Their profit was still there even OP updated the thread weekly.