I want to try out a few PrePaid MVNO's to find one that works best for my area. I have been with Sprint and it is pretty good in my area. We got 4G up and going a few months back, but I have been curious if any others are better. My thought was to try out one at a time. I am trying to figure out the best way to do this. Can I just buy 30 days of each one and see how they perform? It sounds like to try the different networks I could use Straight talk for AT&T and T-Mobile and Ting for Sprint. Am I able to buy 30 days and not cause any problems?