Advertising is generally seasonal as it's a lot more common for people to spend money around the holidays than it is for them to spend money in Q1. Therefore, f

Advertising is generally seasonal as it's a lot more common for people to spend money around the holidays than it is for them to spend money in Q1. Therefore, fewer companies buy advertising in Q1 because the audience of people who will buy their product is smaller. There are a few exceptions to this rule (Mcdonalds, Coke, etc), and they only do that because their business model is essentially to advertise so much you think about them subconsciously. If they stopped advertising for 3 months, this trick would lose a lot of power. This isn't limited to ads btw, when I used to work at a restaurant we'd be noticeably slower during Q1 because people had less money saved (or were more aware of how much they have been spending lately). Similarly, when I worked retail our store "goals" were much lower as well (they usually picked up again late spring/early summer).