An article worth reading:
And I would go one step farther...good angel investing is not just about overlooking rough edges, but instead it is about taking well thought out and calculated risks at a very early stage in the life cycle of a high growth business, thus there are apt to be more rough edges in a typical deal than in deals done by later stage investors.
The simple economics look like this:
1. "Successful" deal(s) return 30x or more of investment (e.g. $100k investment equals $3mm or more on exit);
2. Approx 1 in 10 deals are successful *;
3. Approx. 50% return less than the investment*;
4. Average hold period for a successful exit is approx. 6 years*; thus
5. Average IRR of angel deals is approx. 27%*.
Nonetheless, despite the lofty economic motives there is significant "goodwill" (founders, community, employees, etc.) because many of those companies simply would not exist without the investment and support of early stage angel investors.
*(Numbers based on national averages included in a number of different studies. See Marion Kaufman Foundation for just a few.)