I means it’s a long line. In other words, if you want your cabinets refinished, you’ll have to wait a long time until they can get around to you. Seems like a stupid commercial. You advertise to increase demand. If your demand is beyond your company’s supply of labor then you’re just waisting money on advertising. Very strange.
This expression started to become popular in the 1800s. It is related to the seams in fabric. A seam is where two pieces of fabric are sewn together. If a bag is very full, the seams will begin to bulge apart from the pressure.
The phrase “our waiting list is bursting at the seams” is often used to describe a situation in which there are more people or items on a waiting list than can be accommodated. In other words, the waiting list is so full that it is in danger of overflowing or bursting. This phrase is often used in a humorous or exaggerated way to indicate that there is a high demand for something and that many people are interested in obtaining it. For example, a restaurant might say “our waiting list is bursting at the seams” to indicate that there are many people who want to make reservations at their establishment.