I noticed it keys off of address and name for purchases. Created two accounts, one is home address which i never ship to and the other is my girlfriends house

I noticed it keys off of address and name for purchases. Created two accounts, one is home address which i never ship to and the other is my girlfriends house which had most my purchases except high value items which i ship to work. First account was completely empty on data. Second account had information filled out, seems to use purchases to determine interests. The vendor in question was one of the largest party supply e-commerce stores.