Well, I have an unofficial number for you. The email marketing industry is a $3 billion industry in the U.S. in 2007. It is significantly higher than that in Europe.

Dear Email Diva: Do you have any information on the effectiveness of Forward to a Friend links in emails? Are there specific industries/sectors that are more apt to forward an email? Is it better to offer the forwarding on a Web page or just via the email client?

I work in a world where email is such a small part of the equation and I'm constantly reminded that email has a functional value to a consumer and a business value to a business, but without the Web, search, online media as functional channels, no business task would happen.

I can always tell when autumn is approaching: my favorite magazines publish huge telephone-book-sized bibles on the dictates of fashion. While perusing this year's stack, I see an endless parade of "What's HOT / What's NOT" for the upcoming season. Seems this is the time of year to clear out the old and make way for the approaching changes. Now is also the perfect time for email marketers to a closer look at what we've been doing and weed out outdated thinking. Why not take advantage of the emerging trends this fall, and set your path for a hugely successful …

With the holiday email season already underway, I thought I'd put on my consumer hat and share my list of the most frustrating, consumer-unfriendly aspects of retailers' email programs, in the hope that some will fix them before the season heats up further:

lately, despite the miles of verbiage that I and all my fellow pundits churn out each week on email marketing, I wonder how much we really know about our industry. This was brought home to me recently when I asked my Linked-In network and the Inbox Insiders list to define how big the market is for email marketing. The answers were enlightening. Without revealing the actual number -- which I'll try and provide next week -- the difference between the highest and lowest estimate for the size of the market, both of which came from respectable trade organizations, was off …

Dear Email Diva: What's the current feeling on email page widths and lengths? I know there's been a lot of discussion lately about above and below the fold and sizing for preview pane, but I'm wondering about actual width.