[freeloaderz]

I agree it's vague... you could say for whatever the contributor(s) decide to merge but in any event it seems easy to fulfill the cause, especially since projects need continual maintainence.

At least it leaves some leverage in the hands of the authors/contributors against flat out freeloading. Normal MIT is essentially no strings attached.

[rglullis]

If you don't want freeloading from big companies, why not simply using GPL or AGPL, and offer the possibility of dual-licensing?

[freeloaderz]

It's likely I misunderstand but using the GPL essentially prevents contributing or you lose the ability to dual license (without a CLA)?

The intent of the clause is to encourage both, if you contribute, you can do whatever but maybe it doesn't work that way.

[rglullis]

I think your understanding is correct, but I don't see how asking for a CLA is too much of a problem. It's at least more straightforward than whatever legal spaghetti you'd be getting into just to find something that fits your definition of "fair".