3100 signatures now. Don't slow down, keep sharing this link with people to help push DreamWorks to release the full series on Blu-Ray / DVD. Also send them a letter at 1000 Flower St 91201 Glendale CA. 
Say how much you enjoy or love the show, what it means to you, why it should be preserved, why it's important to have a new home and physical release and when doing so, pointing to the spike in DVD sales for seasons 1-3 when it was confirmed it was being pulled from Netflix. Really push how this show clearly has an audience that still supports the show and wants to still have the ability to re-watch it and that it should still be viewable in it's entirety for that as well as for possible future fans.

Address the letter to any one of the following below,

Margie Cohn: President, DreamWorks Animation (leads both film and television divisions).

Randy Lake: Chief Operating Officer (COO).

Peter Gal: Chief Creative Officer (CCO), Television.

If you want to as well, with the letter, send some branded items related to the show to them. If you draw, put in a picture of your favorite charactrers. 

If you haven't, buy the DVD to support the show and it's actors and creators.