There are different types of pricing strategies: penetration pricing (entering the market with a low price), economy pricing (low marketing and low prices), premium pricing (when the price is higher than the competitors), psychological pricing (example $99, instead of $100), demand-based pricing (based on the demand of the customers).
Delta airlines prices its tickets so that it is less expensive to travel between midnight and 5:00
a.m. than during the day, when there is heavy business travel. this illustrates demand-based pricing.