I think the object of this part is to create a list of people's emails so that you might have a database of people to sell things to. The easiest way to create this email list is to offer them something free. That way people will be willing to sign up for your free whatever it is that you want to give them. Once you create a little form for them to put their name and email into, then you give them the free thing. It could be something they download, or it could be something tangible, such as something physical you send in the mail. It would be more expensive to do that, but the way you get around that is to do a raffle. If you offer something really good, something that costs money, like a gem or a ring or something similar, you could raffle it and still, people would be willing to give you their email just for the act of getting in on the opportunity to win the ring or the gem or whatever it is you would like to raffle. It could be a "Fidget Spinner." It could be anything.
Customer reviews are the "social proof" that encourages people to join in on something. It's one thing for you to tell people to sign up for a campaign, but it's another thing for your happiest customers to say it too. Publish your best reviews from communities like Yelp right to your website. This adds genuine value to your landing pages when people are on the fence about submitting their contact information.
The easiest place to start is with the people you already have on your list. Even though they may not be interested in purchasing your services and products, they were interested enough in your business to sign up and show some type of support. You can use your list of current subscribers to generate more subscribers who are more interested in actually purchasing your products or services.
This practice gives users the option (or forces them) to agree to receive email from third parties. Co-registration is very risky and should be used with caution because it can be confusing to recipients if they did not remember leaving boxes checked and accidentally signed up for emails they did not expect. This can easily lead to spam reports and corresponding email deliverability issues.
For subscribers who may have been on your list for a longer period of time, a small incentive or discount will often get them talking. Marketers should capitalize on word-of-mouth marketing by incorporating email sign-up on viral components, such as features that allow site visitors to forward products, services, wish lists, information online, notifications and more to their friends.
What I will say is that opt-ins on your website and social media will be your friend. Supply traffic coming from Google, Facebook, and Twitter with offerings that they must sign up for. Use a free ebook, a checklist, a free podcast, or even an email course (which you can set up with your autoresponder service) to get them to subscribe to your list.
You can use this strategy to your advantage and increase your email list by giving people an incentive in return for their email. The giveaway could be free access to an e-book, a report, a gift hamper, or perhaps a lucky draw where people enter their emails and get a chance to win. A tantalizing offer is all you need for people to comply. For example: