(1) since it's an article directory it needs to have atleast one article (at the least) promoting it on at least 200+ articledashboard backend article directory,
(2) it's .xml submitted to my.yahoo.com, my.msn.com, google.com/ig/ and google.com/reader/ and also at base.google.com and has it's own press release submitted and published on prweb.com
Examples:
to promote my site w1n.org (short url/redirection/cloaking/adtracking services)
i wrote 2 articles for it:
10 Ways To Benefit From A Short Web Address http://www.nabaza.com/shorturlbenefits.htm
I believe you can still pursue other marketing and promotional methods you have in mind, I'm just sharing what happened to freshdocuments.com as it started from PR0 to PR4 in less than 2-3 months, that's exactly what I've done to it.