Q, Often when ordering from Amazon, Amazon offers a free 30 day trial for Amazon Prime. Amazon has your credit card information, and unless you cancel your subscription to Amazon Prime, you will have to pay for Amazon Prime after the 30 day trial is up. Amazon Prime offers free shipping on all orders along with other benefits. Is one allowed to take advantage of these free trials with full knowledge that they will certainly not continue with Amazon Prime after the 30 days are up?
A. One may argue that the company making that offer has obviously considered that a significant number of desired customers will take advantage of this proposal and follow the process you detailed. Yet they are still willing to maintain their proposal, since after factoring in that loss, they will still be ahead and therefore there is no real damage done. However, Horav Shlomo Miller's Shlit'a opinion is that, it should be avoided, as it can create a Chilul Hashem.
Rabbi A. Bartfeld as revised by Horav Shlomo Miller and Horav Aharon Miller Shlit'a