http://www.kalzumeus.com/2010/09/02/new-trends-in-startup-in...
“You owe me $20, with interest. Don’t worry about paying me back right now. Instead, next time you raise money or sell the company, we’re going to pretend that I’m either investing with the other guy or selling with you."
So if indinero takes more money, the early investors could sell their hypothetical convertible notes to the new investors.
Angel investments are generally illiquid, modulo "you invested in Facebook or some other company which is so hot there is a secondary market and a term sheet practically causes fusion of surrounding hydrogen atoms."
This is a common misconception, and I'm not sure where it stems from. Investors would MUCH rather back Facebook than Mint, that is, investment dollars in a long-term success that becomes essential to the industry goes much further than a product that's acquired relatively early in the company's life.