Your email database is the most important and valuable marketing asset you will ever own. Email is the most personal and direct way of reaching customers. It is opened every day and can help you reach your marketing objectives quickly.

Social media can be a great supplementary tool — to engage prospects and customers, build relationships with them and also generate leads. A lead is someone who visits your website and/or gives you their email. The more leads you have, the more sales you can possibly make. It is a simple and direct relationship.

Social media should be used as a means to extend your brand from the website. Your website should be the central hub of all your online marketing.

Here's how you can use social media to grow your email list:

1. Contests

When doing contests on social media, think about how you can increase the number of emails you receive and not the number of people who "like" or "follow" you. This is because likes and follows are not directly owned by you, unlike your email database.

People who are more likely to be interested in your products/services will enter their email addresses. This enables spot-on targeting via email for your company, unlike receiving a like or a follow from people who might not be as relevant/interested.

2. Facebook tabs and apps

There are a number of tabs and apps available that allow you to capture emails right on your Facebook page. MailChimp is one such service.

Since other social media outlets do not have similar facilities, you can always link back to your landing page.

3. Twitter lead-generation cards

Users can easily and securely share their email address with a business without leaving Twitter or having to fill out a cumbersome form.

When someone expands your tweet, they see a description of the offer and a call to action. Their name, @username and email address are already prefilled within the card. The user simply clicks a button to send this information directly (and securely) to you.

To learn more about lead-generation cards on Twitter, click here.

4. Giveaways

In return for email addresses, you can give out subscriptions, a discount to your e-commerce store, an e-book or whitepaper, etc.

Giving an incentive of specialized/exclusive content via social media can be a great way to not only grow your email database, but also increase your visibility and show off your expertise to impress your customers/prospects.

5. Advertising

By uploading your email list to Facebook and Twitter ad tools, you can exclude the email addresses of people already on your list and narrow in on people who are fans of your page/followers of your account but not signed up for emails.

You can also use Facebook's new look-alike audiences to go after people who are similar to the folks already on your list.

How do you grow your email list via social media? Let us know in the comments below.