The most knowledgeable and renowned marketers in the world view marketing not as an “art form,” but rather as an exact science. This is because marketing, like science, has been researched to death, experimented with since the dawn of time, and studied to the point where we can predict exactly what will and will not work.

I’ve been obsessed with the art of persuasion and marketing all my life, and this obsession has led me to study the very best out there–from Robert Cialdini to Seth Godin to Gary Vaynerchuk. After learning from these marketing gurus, as well as applying and experimenting with different marketing techniques myself for over a decade, I can tell you that there isn’t a product in the world that can’t be sold if you are able to simply flip four key switches that lie hidden within the human psyche.

1. Solution Switch: Show that your product is the answer to their problems.

People do not buy products. They buy solutions. And if you can convince your customers that your product is the solution to whatever problems they might be having, you’ll spark their interest and turn on the most important switch necessary to making a sale.

Take, for example, a sales video designed for an internet business. As an online entrepreneur, what is it that makes purchasing a sales video from someone such an exciting prospect for your website? Is it the creativity and wittiness that’s embedded within a memorable sales video? Or the extra care and effort that’s put into making it? It’s neither of these things, of course, because the real excitement doesn’t have anything to do with the features of the video but rather the leads and potential customers that the sales video can generate. So don’t market your product. Market the source of your customer’s excitement.

2. Trust Switch: Become an authority figure.

Trust is a necessary component of making a sale, and whether it’s consciously or subconsciously, all customers want to know that they’re buying from a legitimate source. The key to flipping a customer’s trust switch is to convince her that you’re an authority figure–someone who is trusted as an expert on the subject at hand.

To illustrate just how powerful the trust switch can be, think about the last time you visited a doctor and ask yourself why it is that you, and almost everyone you know, trust your doctors. It’s because when it comes to health and medicine, doctors are viewed as the ultimate authority figures. So when doctors tell us we should take such and such medication to fix such and such health problem, we listen to them because we trust them–not because we necessarily understand the medical reasoning behind their suggestions. This very fact highlights why trust is such a powerful persuader. The moment we trust someone as an authority figure, we are sold on anything he tells us.

3. Likability Switch: Befriend your customer.

We resonate with those who share our beliefs and ideologies, and we have trouble relating to those who don’t. Similarly, customers prefer to buy from people they like. It’s the whole reason why PR nightmares like the BP oil spill and the United Airlines overbooking incident are always followed by a noticeable decline in business, and it’s also why companies love to publicize their charitable acts of philanthropy.

The likability switch works on a high level with regards to a company’s image, but it’s even more potent when applied at the customer level. Customers want to feel that you’re truly out to help them and that you’re listening to what they have to tell you. This often means trying to understand your customers and tailoring your product or service to solve their unique problems. By befriending consumers and building strong relationships with them, you elevate yourself above the rest of the competition because customers see you not as a greedy corporate identity, but as a friend.

4. Evidence Switch: Customers need proof, not promises.

People are often skeptical about whether or not they’ll actually realize the benefits they hope to get from their purchase. It’s this uncertainty that puts them on edge, as it can be very difficult to ascertain the quality and effectiveness of what you’re trying to sell before actually making a purchase. In the back of their minds, customers are asking themselves a lot of questions: Will taking this marketing course really make me a master salesman and triple my income? Will buying this new outfit really impress all my friends? Will paying for this professional résumé writing service really double the number of interviews I get?

This is where you come in. Provide potential consumers with logical reasoning, quantitative data, or customer testimonials that validate what they were hoping to be true to begin with. Give them hard evidence proving that they will reap all the benefits they desire from your product, and you will easily win them over as eager customers.