Knowing when to pause an ad is not always easy, since results can shift from one day to another. Some businesses watch for a steady drop in conversions over several days before making a move, while others look at rising costs without matching sales. Letting an ad run too long after it stops performing can waste money that could go toward something better. Patience matters, but so does knowing the difference between a slow day and a real decline. What signs usually show that an ad has reached its end?