This topic has been a source of much discussion on the UAV legal groups. Here are a couple of points to consider:
A business who hires an unlicensed pilot to provide pics/video is at extreme risk. The fines for doing so can far exceed the fines placed on the pilot. While the business may survive the fines, the pilot might not be as financially capable. In addition to the fine the pilot is banned from ever obtaining a 107 or perhaps even flying for hobby. This is not theoretical. It's happened dozens of times and some of the fines are huge. As usual, the only benefactors are the attorneys.
The FAA uses the intent of the flight a the time it is made for determining recreational vs business. A 107 pilot has to keep accurate logs for each flight and note the purpose of the flight. Those are generally hand written in a bound logbook. I am a hobby pilot but I have many friends who fly commercially. My rule of thumb is this: If I want to film a particular subject, event or private landscape, I ask permission. If someone asks me to film, I turn them down and refer them to the 107 pilots. It is all about the intent at the time of the flight.
Money is not the determining factor. A realtor who buys a drone to shoot properties is not paid to do it. But's it is commercial use. If an engineer runs home to get his drone to take pics of the bridge he's working on, it's commercial use. If a car dealer brings his son to shop to take pics of the dealership, it's commercial use. If your neighbor offers to buy you lunch to take pics of his house, it's commercial use. If you use your drone to go looking for a lost hiker, it's commercial use.
That doesn't preclude your pics/video from being used later for commercial purposes. A few years ago I asked permission to film an unusual structure. I was granted permission. I created and posted a video on Youtube. Two years later PBS asked if they could use my raw video to include in one of their projects. I agreed and provided the original video. A few days later they sent an email indicating their attorney said they could not use the video because I wasn't a 107 pilot. I referred them to the FAA's definition as well as references to legal opinions related to later use of hobby flights for commercial use. I asked them to have their attorney contact the FAA for a determination. They did and they used the footage.
From a practical standpoint if you go looking for that lost hiker, you are not likely to be called out. But if you are a member of a volunteer SAR team you can't fly unless you obtain a 107. No money involved and you are actually incurring expense to fly your own equipment. However, it is not a hobby flight. It is considered commercial use.
If you plan to use your equipment for anything other than flying for fun, you are at risk. Those who use their equipment legally and have an investment in a business which includes licensing, insurance, writing proposals, travel and all the typical costs of doing business will take a dim view of your plan. They will very likely file a complaint with the FAA and you will get a letter asking you for lots of information and an explanation. That in itself is rather intimidating.
Even though I live in a remote area, there are ten 107 pilots within 40 miles of me. There is a young rogue operator who is shooting commercially. I predict his flying days are coming to a close and those businesses who are using his services will find it very costly.