Bert Wagner shows off a good use of the APPLY operator:
Here we only have 4 nested REPLACE functions. My shameful record is 29. I’m not proud of it, but sometimes it’s the only way to get things done.
Not only are these nested REPLACE() functions difficult to write, but they are difficult to read too.
Instead of suffering through all of that ugly nesting, what you can do instead is use CROSS APPLY:
Click through for the example. This is one of several great uses for the APPLY operator.