When someone signs up for your company's email, do you acknowledge and greet them with a warm, friendly (albeit virtual) smile? Or are they hearing crickets?

Just like you would never ignore someone who walks into your office or business establishment, you definitely shouldn't ignore your new email subscribers. A welcome email is a great way to set up a positive first impression.

Companies are increasingly seeing the value of a welcome email; an email industry study found that 80 percent of brands today send a welcome message; in 2008, it was only 40 percent. Another report states that 53 percent of marketers agree welcome messages best help achieve business goals, up from 15 percent in 2011.

So what makes for a great welcome email? Here are three essentials:

1. Send it pronto.

This is not the time to wait! Fire off that first welcome email as soon as possible after someone joins your list. Strike while the iron is hot and dispatch that welcome wagon pronto, while you're still top of mind.

2. Make your email worth opening.

How do you make sure they actually see and open your welcome message, since you're likely among a sea of other subject lines vying for their attention? One way is to give 'em something they can't resist, like a first-time discount or offer, and announce it loud and clear in the subject line; for example, "Welcome to the List! Get 25% Off Now!"

By reinforcing the action your subscribers took (signing up for the list) and giving them an incentive (25 percent off), you immediately engage them to open the email and get rewarded.

3. Keep in touch.

That first welcome email shouldn't be the last time they hear from you. Don't let too much time pass between the welcome email and the next one. Whatever frequency you promised in your sign-up process (You did include that, right?), you should honor.

A welcome message is an easy way to let your prospects feel important and engaged from the get-go. It shows that you value their interest in your products or services. So what are you waiting for? Roll out that welcome mat!

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