People don't usually show up to auto parts and services locations in the best of moods. Cars are absolutely indispensable to most American lives, so a car in need of parts, repairs, or servicing can put a serious strain on its owner.
Not surprisingly, most consumers waiting for a smog check, oil change, or tire replacement would like their needs met with minimal time spent. A customer who drives to the local oil change station and sees a long line or full waiting room is likely to drive off and take his or her business elsewhere, no one likes waiting in line, after all.
Many people who go to have their oil changed or their tires repaired are under pressure to have the work done quickly because going without a car can be inconvenient or, to some families, devastating. Anxiety leads people who anticipate an arduous wait to take off sooner rather than later to avoid a sunk costs (or time) trap. Many oil change customers, for example, use their lunch hours to get their fluids changed while they eat. If it looks like waiting for service will drag lunch out too long, or if time is otherwise a factor, they'll go find a place without a line.
Every customer lost due to a long line is just one of the many such transactions that tire stores, oil change stations, and auto parts retailers lose every month. Customers who make the trip only to decide to leave are almost worse than those who never come at all - a customer that never was is better than one who could have been but got turned off by the length of the line.
Expanding a business's facilities is one way to counter long waiting times. By opening new berths and hiring more people, a shop can service more cars at a time, but what If the improved facilities lead to more business that just leads to longer lines? Word of the renewed lines will just send people away, until the owners are stuck paying a higher overhead for the same slow turnout. Expanding a business because of natural growth is one thing, but the chances of stopping long wait times permanently are minimal.
Smartphones now allow businesses to line their customers up online, vastly diminishing the chance a long line will even exist to dissuade potential customers. By signing up ahead of time online, a client can select their services, set the time they'd like to be seen, and be placed in a virtual queue. They can watch their number get closer in real time, and when their turn comes up, arrive at the store like the world's luckiest walk-in. In the meantime, they're free to work, play, eat, or otherwise spend their time as they like, rather than being tethered to their car and the shop, and those customers who just swing by will see a busy, bustling location, without the discouraging inconvenience of a long line.