30% returns sounds like a "You give me large amounts of labor at below-market prices today and in return I give you equity!" This sounds like a fairly decent arrangement for an engineer straight out of college who wants to make a go of a startup and, uh, stupid for a professional with an in-demand skill in a sellers' market.

You think their lawyer is getting paid $20 an hour with the remainder to come as a percentage of revenues assuming Marketing does their jobs right? (That's always the stickler with engineers getting equity: you might think you are contributing the most important piece of the puzzle, but really, your contribution can and will be squandered if everybody else doesn't perform at or above your level. There are many, many startups who had top-flight engineers married with "We'll sell pet food on the Internet and make a fortune!"-esque business models.)