hahaha i did a similar experiment about 6 months or so ago. I went to 4-5 newcomers and made some 50% upvotes (given the times it was worth more around 20cents, now less than 10 :P ) and a comment. All of them replied, supported me back with their vote and comment and with the 2 of them we build very good relationships. The other 3 come and go they are not that active but when they come there is an interaction.

I think the key here is the selection progress. I don't know your method if it was just random newcomers or anything else but i had opened about 20 windows of newcomers to finally chose 5 of them that i believed they came here for the same reason as me