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It could be entirely outsourced, where the rental company pays for the entire installation and LaundryCoin automatically wire their profits.

Additionally, every user pays $10 for their smart card. The company would make roughly 5% on transactions, as bitcoin becomes more common place, they could use their card at other vendors.

If the average installation includes 5000 users, that could be a sizable ROI.
I'm open to any other ROI ideas as well.