It does not. Perhaps this is a great first step towards increasing signups.... But I am looking for someone who knows weather or not this would be a good idea.
I doubt your jobs get pulled into the queue. You probably enqueue them and just inform your workers to execute them when the worker's Time.now > the job's run_at. This mean's you may have thousands of jobs in your queue at any moment. An advantage of using cron to schedule is that you won't have as many jobs in your queue at arbitrary times.
True. During my latest interview, Heroku asked me to design a billing/invoice system. I won the position and my first assignment was to work on the billing / invoice system. When I have the opportunity of conducting an interview, I will most certainly use this approach.