Most entrepreneurs are familiar with venture capital, which is typically sought during a firm's early years, and venture capital, which is often used to take a company public or facilitate a leveraged buyout. But many are not aware of a form of private investment called "growth equity"--a capital infusion that straddles private equity and venture capital and often involves minority investments. Smart Answers columnist Karen E. Klein talks to someone whose firm specializes in growth equity: Harrison Miller, general partner with Summit Partners, a private equity and venture capital firm with offices in Palo Alto, Boston and London