What do I have to lose?

I have my time to lose and my time is precious.

You offer to work for free. Therefore there is always the risk of lack of commitment to the work.

By the way, I often receive similar offers from Indian consultancies, by phone or by email. Your offer puts you in competition with them and positions you in the same playing field. If you want to grow a successful high paying consultancy that is definitely not the place to put yourself in.