it's about digital marketplace ,you can sell digital product like mp3,high resolution images etc.I am using django framework.It's a great python framework.if you want to learn django then my suggestion is follow the https://docs.djangoproject.com tutorial and django girl ,and also join the facebook group https://www.facebook.com/groups/python.django/ .it is a great group ,many great django developer are admin of this group like Derrick Kearney ,Daniel Roy Greenfeld(he is the author of best django book "Two Scoops of Django: Best Practices for Django1.8") .And most important thing many great website made in django like Instagram,Pinterest,Mahalo,Bitbucket,Mozilla Support,The Onion etc

Thanks