My latest email subject line split test (for my September 2013 newsletter)
Version #1: Free Adwords Cheat Sheet
Version #2: I’m writing a book
The latter got 14.4% more opens, but fewer overall clickthroughs to my site.
The lesson: as David Ogilvy wrote,
“The headline is the ‘ticket on the meat’. Use it to flag down the readers who are prospects for the kind of product you are advertising”
My second subject line provoked curiosity – and, as a result, got more clicks. But the first attracted more readers who actually wanted the cheat sheet.