I was not aware that, when searching by zip code, the careers site only displays companies with job listings.
(As per the suggestion in the comments of the answer to the above bug report, I am opening a feature request to have this changed.)
While I completely understand the reasons for this (I think Stack Exchange deserves to earn a profit), this is a bit limiting for users who want to find out what kinds of companies exist in a geographic area, whether they are actively hiring or not. It's a great networking opportunity!
I'd really like to see these companies whether or not they have job postings available. I have two proposals:
Could we add a difficult-to-find or "hidden" feature of some kind to include all companies in a zip code search? Maybe a non-prominent checkbox on an advanced search screen or a "poorly" documented search criteria (like "include:all" or "onlyjobs:false")? The incentive for paying for a job listing would still be there since users would need to go out of their way to use this feature (thus reducing "hits" on the company's profile).
If the first isn't palatable (which I could understand), could you at least give companies the option to pay for placement in zip code searches, job listing or no? Companies with job listings would get priority placement (at the top of the list) and/or companies with no job listing would be grayed out with a notice ("0 job listings"). Any kind of search which includes criteria other than zip code (such as "c#") would automatically filter out companies with 0 job listings.
I'm interested in a job listing in another city, but I want to know whether or not there are other companies in the area before I pursue it seriously (you know, in case things don't work in the first couple months).
I am fairly content with my current job, but I want to find out what else is going on in my hometown, maybe connect/cooperate with other developers doing similar/compatible things.
I'll add that companies which have no job postings (yet) have very little incentive to list themselves on careers if they can't be discovered. This proposal would provide some additional incentive to list themselves (which would look good in your advertising: "200,000 companies listed and growing...") and, with option 2, also provide a little extra cash to help pay for improvements to the service.