Here are some tags that that been used at least 20,000 times (placing them in the top hundred most frequent tags). I also counted their subscribers (people who have favourited it), and calculated the ratio subscribers / uses.
| tag | uses | subscribers | subscriber ratio | =========================================================== | visual-studio | 22,179 | 2500 | 11% | | silverlight | 21,915 | 2900 | 13% | | string | 26,562 | 363 | 1.3% | | image | 22,350 | 306 | 1.3% |
Observe the number of subscribers varies greatly from 1% up to 10%. Why's that? The tags visual-studio and silverlight describe popular products that people are interested in. On the other hand the tags string and image describe general things common to many products. Few people subscribe to them because no-one is qualified to answer questions about strings across every language.
Thus I think the list at http://stackoverflow.com/tags should be ordered by subscriber count rather than uses.