This is a guest contribution from Megan Totka.
Building a profitable e-mail list requires more than just adding a newsletter signup form to your website. Attracting and retaining an email list that ultimately turns into customers means finding creative ways to get in front of them and continually providing value.
The good news is that social media can help light a fire under your list building strategy and maximise the results of your e-mail marketing campaign.
Before you turn your attention to your favourite social media platform for list building, here are the best ways to harness the power of social media for your list building strategy:
1: Create High Value Content to Distribute on Social Networks
The term “content is king” has remained on the tips of marketers’ tongues for years. Even in 2017, content remains one of the most effective ways to convert clicks into customers but not just any content.
The key here is to deliver value through your content in terms of answering questions or helping readers solve problems. You’ll need to give readers a good reason to exchange their e-mail address for your content, which truthfully can’t be done if you’re offering run-of-the-mill content.
Consider using content in the form of videos, webinars, downloadable PDF documents, and podcasts.
The content can’t be just any old regurgitated content though. It needs to be so valuable that the reader would pay for it, but you’re giving it away for the low low price of an email address.
Neil Patel does this masterfully, on his QuickSprout blog, by offering a free course on how to double your blog traffic. He values the course at $300 but is giving it away for opting in to his email list.
People are reading your blog for a reason. You must be solving a problem they have or educating them about a specific topic. Offer to give your secrets away for free – well just for their email address and permission to send them more great content.
Take your free course or eBook “list building bait” and repurpose some of it for a blog post or on a landing page. Use landing page software that integrates directly with email marketing software to maximise signups and automate your follow up email campaigns. Once visitors signup on the landing page they are sent into email list segments to start their journey through a pre-set email funnel towards conversion.
This is the content you can use to distribute via your social media channels.
Use your social media channels to drive awareness to the content. It’s great to add some context in your social posts. Tell people what they will gain from the eBook or free course to help drive click through rates and signups. 
2: Carefully Optimise Ads to Target Specific Prospects
When you launch a social media ad, the last thing you want to do is use general parameters to define your target audience and call it a day. If you truly want to get the most out of your list building strategy with social media, you must understand your target market and pay to play.
Take Facebook for instance. Facebook is an affordable yet highly-targeted social media advertising option for all kinds of ventures—including list building.
Create detailed customer personas that outline different people that would be interested in consuming your list building content. If you’re selling digital marketing services, one persona may be a brand marketing manager. Her name is Sarah, is between 27-35 years old, lives in the US, is interested in social media marketing and follows industry blogs like SocialMediaExaminer.com.
Once you’ve created your different customer personas, use Facebook’s lead ad product to drive targeted traffic to your landing page or blog post. 
Once you learn the ropes, you can fine-tune your Facebook ads to match prospects at different points in the sales funnel. This way you can watch how your prospects opt-in to your e-mail list and how your content is encouraging them to inquire about your products or services.
3: Amplify Your Content with the Help of Industry Leaders
If you have great content to offer but you’re a little short on outreach, industry influencers can help maximise your exposure, amplify content, and generate more e-mail subscriptions—all on your behalf.
Think of this as a shortcut to getting a lot of eyeballs on your content without handing over a hefty wad of cash. One of the keys to using this technique is building a relationship with the industry leader and be up front that you’d like for them to share your content. You can also consider allowing the influencer to use your product or service for free as a way to incentivise them to spread the word.
Use platforms like BuzzSumo to find influencers in your niche who are already sharing topics closely related to the content you want them to amplify.
4: Best Practices for On-Site E-mail Signups
Once you have your content published on social media, you can’t forget what happens when visitors land on your website. It’s important to optimise your landing page to increase the amount of conversions and users opting into your e-mail list.
One important consideration to keep in mind is the length of your opt-in form. It’s best that you use as few fields as possible, while still capturing the information you need for personalised email messages later on. You’ll also need a direct call-to-action with an obvious button front-and-centre.
This is a basic landing page from Trulia that shows a simple signup form with only one opt-in field.
Have you been using social media to drive sign-ups? What’s working for you?
Megan Totka is the Chief Editor for ChamberofCommerce.com. Chamber specializes in helping small businesses grow their business on the web while facilitating the connectivity between local businesses and more than 7,000 Chambers of Commerce worldwide.