In the world of startups, getting venture capital funding isn't exactly easy. It's sort of a business of who-knows-whom. And getting in front of investors can be key. Enter the accelerator. These are for-profit business incubators that invest in groups of startups, give them advice and mentoring, and connect them with other investors. One of the biggest tech accelerators is Y Combinator. It has funded companies including Airbnb, Instacart and Dropbox. Marketplace Tech host Amy Scott talks with Michael Seibel, who leads Y Combinator's accelerator program.