In just about every due diligence engagement I carry out, the VC and I spend a lot of time on scalabity of the software architecture. The company whose software architecture we are evaluating usually has a good track record of successfully scaling up on quite a few technology and business dimensions. If we extrapolate the historical growth rate a few years into the future, the company really looks attractive. The concern, however, is that the company might run into a hard barrier for growth.