What would I do? I guess firstly I'd try and be as realistic as I possibly could, what I mean bu that is to approach this in a real hard-ass way as opposed to

What would I do? I guess firstly I'd try and be as realistic as I possibly could, what I mean bu that is to approach this in a real hard-ass way as opposed to a "its my idea, so I should keep x" kind of way. But you don't seem like that kinda guy/gal. One of the main things you should take into account is longevity of the relationship - if you think this guy might be around for a few months, then his job is done and he's off elsewhere - you'll want to make sure his stock has a vesting type option to ensure that if he does take the stock, and leaves in a few weeks because I don't know, say he gets a better offer, his wife has a baby - then you'll want to make sure he doesn't take 40% of the stock with him. In the same breath you'll want to make sure you take into consideration how much effort/available this person can bring to the table. Do they already have a full-time job? Are they just bringing you the odd-contact? Or are they full-blown in it until the death? I would also put a serious value on this guy. I suppose the short answer to your question "what would I do" is honestly think, if I continued on my own path for x, how much could I achieve alone? If what I can achieve is quite a lot, then would I be 30% better off (I mean in stock terms) waiting until I have something to show and THEN bringing on this guy (or filling this role, even). Obviously totally depends on your business type. Additionally, the old school answer to this question is essentially the golden rule - if you give this guy 40% of your business, will your 60% be worth more than the 100% originally was because of the effect he will have on the business? Best of luck.