Welcome to Yardsellr! I'm part of the Yardsellr team and would be happy to tell you about Photon$.
Photon$ are like money that you can use to buy anything on Yardsellr! Photon$ can be won by taking certain actions on Yardsellr.com, like buying, selling and commenting on listings or just for signing in. Look for the dollar sign ($) for opportunities to win Photon$.
To use your Photon$, just click "Buy Now" and follow the instructions from there. Just so you know, Photon$ can be used toward the price of the item. Shipping and the Yardsellr slice can be paid with either credit card, debit card or Paypal.
Once you log in to yardsellr.com you can check the status of your Photon$ balance at the top of the page.
Thanks! Hope you have a great Yardsellr day.