Divyachi Avas

Some sites giving information about Divyachi amavasya that is followed in Maharashtra (also in Karntaka and Andhra Pradesh under different names). I am trying gather as much info as possible for this less known festival:

http://www.shreedarshan.com/ashada-amavasya.htm
http://www.karmarkarfoundationmumbai.org/karmarkar_english/Html/Festivals2.html

I can see that there is lot of fascination for lamp worship in India. Looking for a reason for that.