There is an alarming statement in D&C 93. It follows the definition of truth found in D&C 93:24: "Whatsoever is more or less than this is the spirit of that wicked one who was a liar from the beginning" (D&C 93: 25); meaning that we are all required to find the truth. Anything more or anything less is evil and means we have been deceived. In addition, the follow up to the parable of the Ten Virgins found in D&C 45:56-57 warns everyone that the five foolish virgins who will not take truth as their guide are going to be hewn down and cast into the fire.
These decisions about what truth you must accept are important, but can only be made by trusting the Spirit. You should look to the Spirit for the answer to where and what is truth in this day of so much deception. Marketing, by its very nature, is deception. (See, The Marketing of Evil: How Radicals, Elitists, and Pseudo-Experts Sell Us Corruption Disguised As Freedom, by David Kupelian) All of modern commerce is based on deceiving you. Making you think you need something when you do not. Exciting your envy to get you to purchase something you really don't need. So when it comes to the truth, you will need to demonstrate some "sales resistance" to Satan, and not be fooled into rejecting truth although it comes from a lone voice, crying from the wilderness (as has been so often the Lord's pattern in the past).