There is hardly anyone who doesn’t get excited at the prospect of winning something without making an effort and that too, for free. And if subscribing and giving my email is all it takes, I, for one, am going to participate! Think about it. If a landing page asks you for your email address, why would you give it, unless it was going to give you something in exchange?
Visitors are more likely to stay engaged with your business if the pop-up is relevant to their specific needs and interests. This means you’ll be able to organically increase your subscription rate by communicating the right message at the right time to each segment of your audience. For example, if a visitor shows a specific interest, the most relevant pop-up will appear.
Include social sharing buttons and an "Email to a Friend" button in your marketing emails. That way, you'll gain access to their friends, colleagues, and networks and expand your contact list. At the bottom of your emails, include a "Subscribe" CTA as a simple text-based link so that the people receiving the forwarded emails can easily opt-in, too.