Making money (or at least cutting the cost) from library and archive collections.
Amazon.com integration can be a nice revenue stream, generating 20% returns on every sale made through a link from your site. Koha is an ILS system that can import CDS/ISIS format exported from greenstone.
In House sales
Sometimes downloading huge files, especially if there are many of them, can be a hastle. Providing duplication services can help both the library and the end-user. CD / DVD duplication using the greenstone export to cd function can be a great way to publicize your library as well as make some mooney on the side. Creating a versatile structure to support this feature is lacking from the end-user end, however it can be done with a versed librarian behind the wheel of the collections
Out source sales
Sometimes media, such as posters, maps, videos, and even complete books can be integrated with websites like Allposters.com and Zazzle.com to create a high-end product. Libraries can sell directly from their site, or purchase duplicates for sale in the gift shop.
Google books provides an interesting opportunnity along these lines