Libraries using Twitter & Facebook

Public libraries in our region (Yorkshire and East Midlands) have not on the whole been early adopters of Web 2.0 technologies. At the SINTO Members' Day on 26th June there will be a presentation from Rotherham Libraries about their use of Facebook and Leeds Central Library has a Twitter feed. Apart from that I know of no other public libraries using these tools. (see the list provided by Mike Stores on the JISC Lis-pub-libs list.)
Does that indicate that public libraries in our region are old-fashioned and out-of-date? Or does the low uptake mean that most libraries have concluded that this is just not an effective marketing tool and there is no point in wasting resources on it? The Leeds Twitter feed has 93 followers (i.e. people who are receiving the tweets) but over half of these are other libraries or organisations and only 40 are individuals who may, or may not, be library users in Leeds. This does not suggest that Twitter is having a large impact in the target audience.
Twitter is often portrayed as a useful way of communication with a younger demographic and one which libraries need to reach out to - but if the basic library offer is not attractive to this group then no amount of Twittering will work on its own. However, as part of a package including greater use of e-books and on-line services, Twitter could be a useful tool. When we walk through the doors of our libraries and into our place of work we cut ourselves off from our customers. No matter how good we are at doing our job we always have to reach out to our customers and potential customers. Twitter and other Web 2.0 tools are one way of doing this.