Best day to email

We were asked what our views were on the best day to email & guessed (well, more opined based on anecdotal evidence) and said "Thursday". I nearly added "lunchtime". I was asked why and felt iffy about revealing anecdotal material.

So I googled it. And found this:

- Fridays for open-rates, but Sunday has best click-thru rate.
- Friday has open rate of 21% and click-thu of 4%
- There's no best day
- How to use Google Analytics to derive the answer

Here's the e-roi data - you'll need the B2C data.