In this situation, what's a fair equity share?
enjo: As to what is "fair" that's between you and the founders.You do need to be ready for some serious shock come tax time if you do take on additional equity. Equity (from the IRS perspective) is income, and is taxed as such. If the valuation of the company is high (not the cash value, the fair market valuation) then taxes are going to be through the roof even though you haven't received any cash.