The model of going to the store and buying software is dying. Where did they get the size specification for a retail software box anyway. It used to be a binder, then it turned into a cardboard box that held diskettes and a manuel. Finally, when CD's came out, the box shrunk a bit...but you still get a cardboard box that is printed with the sweet benefits and pictures of what is inside. You take it to the register, you buy it, you take it home and install it. Can you believe that this is still happening right now in this day and age when the internet is everywhere and that just isn't necessary?
Linux suppliers like ubuntu are doing it right and creating a virtual software center where you go out and browse an online catalog of software that is available and you download what you need...it is installed and updates are maintained for you as the software improves over time. The "free" open source software model has forced that industry to cut costs and be efficient with the delivery and maintenance of software.
For SaaS products, it is the best of both worlds. SaaS software vendors actually generate recurring revenue for the software and SaaS software vendors take advantage of optimized systems to purchase, deliver, and maintain the software for the customers. This puts more investment into the software itself and not into the disposal packaging and expensive, inefficient distribution systems of the past...er...present.
The selection of software available at your local Best Buy is dwindling while the options available to you for subscription based services are increasing. This is a good thing. Be sure and support your favorite SaaS solution and keep the innovation coming.