Endorsements are the fuel of crowd-voting campaigns. They are an incredibly easy, free and effective way to build grassroots support for a people-powered candidate that you like.
Your endorsement is extremely valuable because it can bring awareness of a good candidate to your family and friends or the people who follow you on your social channels and who trust your judgement.
Establishment politicians typically tout endorsements from big money donors and partisan career politicians interested in maintaining the status quo. Good Party endorsements are a way for 'we the people' to take back this power for ourselves and make truly grassroots campaigns go viral and win.