Yeah that's all it does. Takes your total annual (estimated) usage and divides it by 12, so you end up "overpaying" in the summer and "underpaying" in the winter, but it's ultimately the same cost.

https://www.rienergy.com/RI-Home/Bill-Help/Budget-Billing

>Gas company clearly must make money on it or they wouldn't offer it.

Someone on here had said they tried to sign up and there was a surcharge, but I can't seem to find it on any official documents. It might be a program RIE is required to implement by the state, so it's not (directly) a money-making endeavor. But it still does seem of limited use to me.