Assume that I'm a badass software developer who specializes in scalable web-based systems. In that case, you can also assume that a.) plenty of people approach me with their middling ideas all the time, wanting me to work for peanuts/equity, and b.) I already have a job.
What else could he offer that I might find motivating?
To answer your question: Offer a real chance of success.
Success is my personal financial success, not just company success and it has to be financial success.
How many POS startups are out there that will never amount to anything?! 50% of 0 is 0.
Prove that you (the hustler) have what it takes to make this opportunity succeed.
Prove that this opportunity WILL succeed.
Give me enough equity that will pay 3-5X my base salary with the low/conservative projections and 20X my base salary with the homerun projections. That's based on a 2-3 year commitment.
Give me the ability to do my thing (hacking) without you (the hustler) meddling in it.
It's pretty easy, if you're a really good hustler who's actually out there making it happen.