We have three founders and it's been pretty solid. It's very hard to have a decision impasse with 3 people. We all defer to each other's area of expertise and in the (many) areas where were are all stupid (but still have the make a decision), we defer to the majority (or occasionally, it's a "loudocracy"... :-) ).<p>Another downside that I don't think was mentioned is that your "ramen profitable" number goes up by about 50%.<p>Even with that, I think the 50% bump in (free and maniacal) manpower plus the extra perspective is totally worth it.<p>I always say that it's better to optimize your CHANCE of success rather than the magnitude of it, should it happen. Hard to argue that a good (free!) co-founder wouldn't do that.