Keywords In Image Files.

One of my websites gets hundreds of visits a month from people who are
searching for images. I'm not sure how valuable those visitors are, but I
didn't have to do anything very special to get them.
Google Images - http://images.google.com - makes it easy for people to
search for graphics online.

To take advantage of this, when choosing the file name of an image on your
site, use an appropriate key phrase, for example, "book-ends.jpg" if you're
promoting book ends.

Here's a tip I just discovered...
When I searched in Google Images for "book ends" I discovered that the
very first search result was for a page which did NOT contain a graphic of
book ends!

Instead, the page contained a "book ends" LINK to a book ends graphic on
a second page. It if suits the design of your site, you may want to
experiment with this technique.

I'm not sure how much use traffic to images is, but if it's ADDITIONAL traffic
you can get simply by choosing image file names carefully, it's worth having.