aaudette - 6:20 pm on Mar 28, 2007 (gmt 0)

First of all, you rightly point out that the market niche will factor in here.

Secondly, when posters are including times keep in mind that they'll vary depending on geographic location. Saying that 11:00 is the absolute best time for an email drop is meaningless - if it's sent from Oregon it's already way past lunch in NY. And forget about the rest of the world.

I've had good experience with Wednesday's, but Friday's are surprisingly good depending on the flavor of the newsletter. Sending at 00:01 -8 GMT is our preference, but I know publishers who swear by 10am EST for every email drop.

There's no definitive answer here, and any positive responses to an email campaign will likely fluctuate wildly from season / time / day / moon phase.