Editor's note: Jason M. Lemkin served as CEO and co-founder of EchoSign, the web’s most popular e-signature service, from inception through its acquisition by Adobe Systems Inc. in 2011. If you are in a reasonably hot and/or interesting space, and you have a modicum of traction or even perceived traction after X months or X years (likely years in SaaS), you’ll probably have a day when you get an M&A. And later, two or three or four.