Is DevOps restricted to companies with SaaS products?
Absolutely not!

DevOps is all about breaking down the traditional silos (departments) in order to be more efficient.

Better communication between teams, improved visibility and reliable and automated process are ways to achieve a better product.

I used to work for a big media company where we would support an internal tool and develop public-facing websites. 

The benefits of DevOps in our case were the following:


Through continuous building, we let know the development team earlier rather than later if there are integration or build problems with their code. They can fix issues while their mind is still on the piece of code they just committed.
Through continuous testing and delivery (into QA), we enabled the QA team to find problems earlier and report them earlier. This reduced the time it took to find and correct bugs as well as reduce the complexity of these investigation.
With out log collection &amp; aggregation tools, we gave to the developers access to something they wouldn't usually look at (they were very keen on the debuggers :) - understanding how logs are seen and used by other teams improved the overall quality of logs
We often shared information and created documentation to share knowledge between teams, trying to break down walls. By understanding the Ops' needs, we create a few guides for what should always be kept in mind when bootstrapping an application (where/how to manage properties, etc.). By understanding the Dev's reality (code more features, faster, gogogogo!) we were able to have the ops create servers and clusters that were better suited to the dev's needs.
The overall quality of deployments was greatly improved too. Deployments were handled by our team, so we had perfect visibility on both Ops and Dev. This eliminated many issues related to the "code hand-off" where the dev would hand over a package and one-page document to the ops saying "Install this!".


Overall, I would say that regardless if you are updating your production environment once per day or once per month and regardless of how many customers you have or your business model, every enterprise can use better communication, better tools, better visibility, faster feedback, etc.