There are more good reasons to continue to advertise during slow times than there are not to.
If you aren't advertising when it’s slow, it's likely because cash flow is tight. If that’s the case, use the slow time to learn how to do some simple social media marketing on your own. Not only will you learn a valuable skill, the next time you hire someone, you’ll have a better understanding of what you need them to do.
You want to keep up your advertising all the time because you always want to be top-of-mind for your customers. When they need your product or service, they should think of you. Plus, if your competitors are quieter because it’s a slow time of year, it will be that much easier for you to get your customers' attention.
If you have a warm weather seasonal business, at face value it might not make much sense to advertise in the winter, but it’s during the winter when people are planning their spring and summer activities.
And if you know when you’re going to be busy and when you’re going to be slow, you can take advantage of that knowledge and advertise in the build up to the busy season. A slowdown may also be a good time to offer a nice discount to generate some revenue you might not otherwise have gotten.
Think of slow times as a good time to get in front of new customers and improve your business!