If you're like most of us, we upload files without really considering the name of the file. For example, our pictures are PIC 0231953.jpg or an audio file might be AAA108429.wav. It's an easy method for us to use and it is simple to make sense of on the user side. We add text in for the file links that provide the actual title of what we mean instead of the obscure file name.
This method doesn't appear to cause any confusion. But what you might not realize is that by not naming the file using keywords that you are optimizing for, you're missing out on a prime opportunity to let Search Engine spiders know a lot more about you. Your users know what your files mean (they can see the pictures, hear the audio, and see the alt tags you put in.) Spiders on the other hand aren't going to experience your site in the same way.
So what does this all mean? Take time to name every file you upload using keywords so your SEO results will increase.
Usually about this point someone raises the issue that naming a file using keywords takes a lot longer than simply uploading it with the pre-assigned name. That's true. On the flip side, it also takes much longer for someone to find your website if you're not on the first page of Google (if they'll even find you at all if you're past the first page). The benefits of taking the extra time to focus on SEO is that it will lead to more people finding your site, more conversions and a greater ROI.
So how do you name a file? Simple--use words that describe the file and also what your site is about. Maybe you will begin to put your speakers name and program title in the file name along with a topic. Perhaps it is as easy as having your on-air hosts name and station call letters included in photos from the last station event. It's the little things that will eventually add up and move your page higher in ranking.
A word of caution, though. Just like we've talked about before, you can't "keyword stuff" file titles...meaning, you cannot jam it full of words that are not relevant to your file. No having a picture of a flower and naming it after your program, station, on-air host, etc. It has to actually be relevant. Otherwise you'll be marked as a spammer. On the flip side, though, any file you upload should be relevant to your site. So any file name should be utilizing keywords without any fear of appearing to be a spammer.
Change is absolutely the constant of SEO. Keeping up on the small areas (like file names) is just one way to set yourself ahead of another site. Each time you're higher in the results, the visitor increase to your site is quite significant.