Hardware sales would be an excellent business model for open weights. Nvidia is already on it with their Nemotron models. Any new LLM/NPU hardware companies would want to so the same, if noone else does it for them (Chinese labs currently do).

Selling managed self-hosting solutions would be another. That is the business of that recent American company.

Selling fine-tuning services or similar adaptations is another. That is what Unsloth is going for, I believe.

Most likely any sound business strategy is going to be of "commoditize your compliments" type. There are many complementary products to open-weight - some probably not invented/discovered yet.