Certainly this is a great idea. However and respectfully and with a great deal of admiration perhaps we have a few other issues to look at on the other side of the coin.

1. Given the short fuse of many Webmasters and the huge size of some of your Directories, I can almost guarantee a few Spam complaints. It's safe to say that most of us are on dedicated boxes with a bit more leverage but as a guess, mail 10K and I bet you get a few dozen. I certainly don't wan't to debate weather this is Spam or not and only mention this as an issue to think about. I like the idea and would use it :)

2. Could anyone guess at what the success rate would be? In some respects this could be related to my first point: risk/reward. Run the chance of a Spam complaint in return for x number of positive responses. I mean, I get dozens of we added your site to our bla bla bla and never have the time to respond and rarely the inclination. Obviosouly, your Directories are all high quality and not some less than perfect link farm at the bottom of the ocean.

geek/talk Forums @ GeekVillage.com
Quality Forums For Webmasters & Merchants