We hear how e-mail is becoming obsolete and social networking is morphing into the medium of choice for online communication. But in the business-to-business community, it hasn’t happened yet. Seventy one percent of B2B firms use e-mail marketing. And e-mail is the method of commercial communication preferred by 74 percent of all online adults.

What are the best practices in e-mail marketing today? To begin with, instead of renting lists and sending your e-mails to cold prospects, get people to opt-in to your e-list. Then concentrate on e-mail marketing to your house file. E-mails to house file lists generate two to three times the click-through rates (CTR) or higher than outside lists. And e-mailing to your own e-list eliminates list rental charges of $100 to $250 or more per thousand names.

How do you build your own opt-in e-list? The most popular method is offering a free subscription to an online newsletter. You can also offer a free webinar or special report. To get your free offer, the prospect must submit his or e-mail address and name, thus opting into your e-list.

How often should you e-mail your subscriber list? The biggest worry among marketers is offending people on the e-list by e-mailing to them too frequently. But consultant Amy Africa says the biggest mistake marketers make is not e-mailing their lists enough.

Here’s a method of determining the optimal e-mail frequency for your e-list: Measure the opt-out rate, which is the percentage of subscribers who unsubscribe after an e-mail is distributed to the list. If your list has 10,000 names and your opt-out rate is half a percent, you will lose 50 subscribers for every e-mail you send out. As a rule of thumb, your opt-out rate should be 0.1 percent or less.

To increase e-mail frequency, add one more e-mail to your weekly or monthly schedule. Then keep a close eye on your opt-out rate. If it stays the same, you can safely increase your e-mail frequency to the new level. If it spikes, cut back to the old frequency.

One reason for opt-outs other than frequency is the quality of your e-mails. When you send useful content, your subscribers will thank you by remaining loyal subscribers and opening, reading, and responding to your e-mails. On the other hand, if all you send are sales pitches, they will unsubscribe – and even those who don’t will stop opening and reading.

A good rule of thumb is that at least 50 percent of your e-mail messages should be content. If the ratio of content to sales falls below 50 percent, your opt-out rate will increase and your open rates will decrease.

What about the content and copy of your e-mail messages? Here are a few guidelines and tips:

** Begin with an engaging headline or lead-in sentence. You need to get a terrific benefit right up front.

For instance, Orleans Coffee Exchange provides coffee by mail. They sent an e-mail to past customers who once subscribed to their coffee service but had dropped off the list. The headline: You Still Drink Coffee, Right? It struck a chord because of course, in almost every instance, the recipient still drank coffee. The open rate was 52.3 percent and the click-through rate was 34.6%. Dozens of old accounts were reactivated.

** In the first paragraph, deliver a mini-version of your complete message. The reader should know who you are, what you are selling, and why he should be interested.

** Within the first couple of paragraphs, state the offer and provide a hyperlink to a landing page or another immediate response mechanism.

** After the first paragraph, present expanded copy that covers features, benefits, proof, and other relevant information.

** The offer and response mechanism should be repeated in the close of the e-mail. But they should almost always appear at the very beginning, too.

** Use wide margins. Limit yourself to about 60 characters width per line.

** Take it easy on the ALL CAPS. Words in all caps give the impression that you are shouting.

** The tone should be helpful, friendly, informative, and educational, not promotional or hard-sell. Information is gold on the Internet.

** Be concise. Readers are quickly sorting through a bunch of messages and aren’t disposed to stick with you for a long time.

** Regardless of length, get the important points across quickly.

An effective way to organize your e-mail copy is to use the motivating sequence, a formula for persuasive writing that works in all media. The motivating sequence is (1) get attention, (2) state the problem your prospect has, (3) position your product as the solution to that problem, (4) offer proof that your product is indeed a superior solution, and (5) ask for action.

A company distributed an HTML e-mail with a picture of its new hand-held 7530 computer designed for rugged service, especially at cold temperatures. The problem statement read: Do you need a hand-held computer that operates at the same temperature as cherry berry fudge chunk ice cream … -22° F?

Keep in mind that you need not fit all or your product copy and sales points within the e-mail itself. You can tell part of the story in your e-mail and let them click through to a landing page or other web page for the balance.

What’s the ideal length for an e-mail? In most instances, shorter is better than longer. So if you have a lot of information to communicate, place most of it on a landing page and hyperlink to this page in your e-mail.

As stated earlier, have a hyperlink at the beginning of your e-mail, one at the close, and preferably one or more in the body. Testing shows that the more hyperlinks there are in your e-mail, the higher the click-through rate.

One of the biggest influences on open rates and click-through rates is the subject line. Split tests of subject lines have shown click-through rate differences of 25 to 50 percent and in some cases higher. Keep subject lines short. Craig Stouffer of PinPointe says that subject lines 40 to 50 characters in length significantly outperform subject lines of 70 to 80 characters.