Positioning determines the place your product takes in the customer's mind. It isn't an ad or a pretty logo; it's the clear answer to the customer's question, "why should I choose you?" Without the right positioning, even a strong product fails to sell.
Wrong positioning is the most expensive marketing mistake. Sometimes the product is excellent but shown to the wrong person with the wrong promise — the budget burns and no leads come.
How positioning is built
Positioning sits at the intersection of three things: the customer's real problem, your unique strength, and a promise a competitor can't make. Get those three right and the offer, creative, and copy fall into place on their own.
In practice, positioning must be tested: write 2-3 variants and run them in advertising in parallel. Whichever brings cheaper, higher-quality leads is the right positioning.