As with the previous cycle, we are once again seeing the formation of many new incubators (Om has a post up which inspired my post). Having co-founded an incubator and having observed a bunch of others over the years, I have a theory about what works and what doesn’t. I believe that the only two versions that work are: accelerators, such as YCombinator and Techstars, and “foundries” (my attempt at a neologism), such as Idealab and Alleycorp. Let’s start with accelerators. These are characteri...