The entire Minted community votes on submissions to Minted Challenges! This includes artists, customers, and general art and design lovers. You’ll need to be logged in to your Minted.com account in order to vote.
While it's great to get the word out about voting and encourage people to check out the challenges and your work, it's not necessary to actively promote your design for voting and ranking purposes. The pool of Minted voters is very large (e.g. many Minted customers vote on the designs) and we do careful analysis to eliminate unfair voting behavior.