Clarifying the use of $job when queueing closures

I feel the most common use case for queues in Laravel 4 would be to defer processing of a job like queueing e-mail for later. For most cases, you will want to delete the job off the queue after you're finished with it, however the documentation defaults to showing closure queueing without $job as a parameter. Maybe I'm dumb, but it took me quite a while to figure out you could do that (or how to do it) with closures.