There are many different ways for libraries to offer subject guides to their users. One of the easiest ways is to post their guides to a static web page, where the person maintaining it will need to have some level of XHML skills. This is made easier if the library is part of a larger organization that has specific branding and online policies, in which case the library only needs to update their content and not the CSS or formatting of the page. Another option is to post documents in a word processing format to the library server that can be accessed via a library's homepage. And yet another option is to pay for a guide service that allows the library to add different types of content using different technologies, such as Libguides from Springer share that enables many Web 2.0 capabilities for libraries to display with guides.
Some options have higher costs associated with them and in some cases those costs give greater value to a guides content, but in most cases the library maintains absolute control over the content and the guides still have a static nature to them, where the librarian is the only person that can modify the guide.
This is where wikis and social bookmarking services can really enhance library subject guides and continually add value to them. The social aspects of these two technologies are really what set them apart from more traditional technologies already in use. Wikis and social bookmarking rely on the combined 'power' of the library and the users or patrons for keeping the materials up to date and relevant. In this way the responsibility of keeping a guide current rests with everyone who would use it, not only a librarian.
In a related fashion, using social bookmarking for subject guides allows more participation from those using those resources, as Melissa Rethlefsen briefly discusses in her blog post Tags Help Make Libraries Del.icio.us. This collaboration can only benefit a library's subject guides, librarians would receive instant feedback as to whether specific sources were useful and it would allow users to add more useful sources as well. A librarian would need to monitor these bookmarks for appropriateness.
Social bookmarks are a low cost way to provide subject guides to library patrons. This is especially true when a library cannot afford to use Libguides or other technology services. Slightly more tech savvy librarians can create a link-rolls and feed these bookmarks into their library Web site using RSS. This makes social bookmarking even more versatile for libraries and perfect for groups or communities that are not already familiar with each other. This is why social bookmarking tools are a better choice for library subject guides than using wikis.
Bill Johnson's blog post, When to Use a Wiki?, discusses when and why wikis are effective and not effective. He states that wikis work well for groups that already know each other, when there is a clear final product in mind, when a consensus needs to be reached and not for opinions, and when there is a short deadline involved.
Most of these aspects of collaboration that lend themselves well to wikis do not lend themselves well to creating a subject guide when compared to using social bookmarking for the same purpose. Subject guides are dynamic, being constantly updated, the more people that contribute the better (in theory), a subject guides' contributors do not need to know each other to make positive additions to the guide, and since guides are always evolving there is not a deadline.
When a subject guide needs to be created and the choice is between using social bookmarking or a wiki, social bookmarking is the better tool to use.