Just because you put something up on the Web doesn’t mean that people will find it. Think about how your users locate your collections now and how this may or may not change with digitization. Some of your users will likely find digital collections the same way they find the analogue ones—through a library catalog or an archive’s finding aids. Helping these users can be as easy as providing a link to the digitized resource in the usual places they look for materials. Optimizing the number of people who find and use your digital resources should start with creating good bibliographic description of the resources themselves. In short, there is little point digitization something if you don't have good metadata to enable people finding it.
But opening up your collections to the world also means that your potential audience is much wider. Is your library’s catalogue indexed on the Web? If someone searches for the title of the work you are going to digitize, will your site come up in the first page of search results? If providing good descriptions is the first step, the next is to make sure that those descriptions are exposed to search engines. This process is often referred to as 'search engine optimization' (SEO) or 'search engine marketing' (SEM), but both of these simply refer to the practice of increasing the volume of traffic to a site by improving visibility on a search engine results page.
Marketing is in the very genes of libraries and museums and should be extended to our digital collections as well. In 1931 SR Ranganathan wrote:
It is no wonder that, when the library has been extending its scope, changing its outlook and altering its very character and functions, there should not be adequate understanding among the public as to what has been going on.
In other words, 'build it and they will come' just won't do.
SEO is one way to get your collections found, but there is also another way -- something that libraries have been doing for many years. Remember the humble subject guides that even today are still printed out and put up in libraries? LibGuides is a clear (and clearly successful) extension of this, but so are creating subject-specific guides to digital collections. In 2004, we began doing this for the Open Collections Program and Megan and I have written and spoken extensively about the role this played in a successful outreach campaign. These are still some of the most heavily used parts of the site, in large part because they are the most easily found. I was very pleased to see the DPLA take the same approached recently with their online exhibitions as well as those on Europeana. These are great ways to get people into your digital collections and to show them what you have.