robzilla - 7:11 pm on Apr 21, 2011 (gmt 0)

Only testing will tell you whether or not it works (and with what phrasing). If appropriate, you could ask for feedback from your regulars. I would certainly avoid trying to tell them what to do; make it look like a friendly request, a plea (but no begging), and I doubt they'll be "too meanspirited to click" (that is, if they like your site).