Private proxies/ dynamic IP question

Lets say, hypothetically speaking, that I had a dynamic ip address, or that i had several private proxies, isn't it possible to fill out my own surveys/offers and make myself money? Is there a way for them to tell that the person is using a proxy? Or is just a frowned upon method because of ethical "cheating" reasons?

User agent, Mac, System name. I can keep going.

Sooner or later you will be caught, doesn't worth the effort.. better try to build a website with traffic and get real leads