Quick Question about public internet access.

I am a noob here on BHW. Been doing a lot of reading and I've learned alot from you guys. Currently I am using CrakRevenue on my Tumblr site and making ok money ($10.00 in fist 48hrs). So basically I get paid when someone clicks the link, adds email and username and then verifies their email address. What I wanted to know is, can I go to a local place that offers free wifi and sign up using real emails that I can verify and make money? I dont know if they can track things like that if I use multiple devices. Any help would be appreciated. Thanks in advance.