Every business has some periods during the year where typically business slows down a bit, or more competition enters the playing field.
For example, for dance studios, we've seen, over the years, that the start of the school year can be a time where the cost per lead increases for them because there is a lot more competition.
For some businesses, summers or winters can be typically slower.
Always keep this in mind as you factor in the costs for your ads.
With that said, even if you think right now might be a slower time for you, I don't suggest you stop advertising.
I would recommend trying out different images and videos to see if you find something that works.
We've managed to do it for our clients, but it takes patience as you test different images and videos.