My experiences through GrubHub's IPO from start to finish
Very interesting and educational read. Even if you know a little bit about how IPOs work, reading through the complete timeline helps understand the roles and the steps involved.One question that came after reading:    The underwriter won’t move forward unless they get a very
    high percentage (99-100%) of employees/shareholders to sign
    a lock-up.

What are the incentives for employees to sign such an agreement? It sounds like the only point in the process where an (organized) group of employees could have some leverage?