A decade ago, most companies did not give their customers any tracking information. If the customers called and asked about their packages, they could look them up and tell them where the boxes were located, but this was done on a case-by-case basis. Most people did not ever check unless they thought that a package had been lost because the process simply took too long. Customers did not think it was worth their time, so companies did not worry about it.
In the modern day, though, customers almost always want to have tracking information for their purchases. When you use industrial UPS systems, you can simply send them a link that they can click. It opens in a new browser window, and it automatically takes them to a page that gives them tracking data for their package, using the order number. They can see where it is every time that it is scanned, which lets them know if it has arrived in town and if it should be dropped off that day.
Customers love this system because it is so easy to use. They do not have to make any phone calls. They do not even have to know what website to go to or what package number relates to their order. As long as they click the button, the system does everything for them. Since this is now an expected service, you should make sure that you give customers this information so that they do not pester the shipping department.