Hi. There are several proven approaches you can test to see what is more effective to your specific public. I can elaborate them better after getting some further details about your marketing strategy.

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1. Turn subscribers into affiliates
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Just offer a discount or any other benefit which your subscribers would appreciate. Such tracking is easy to do with affiliate ready-made tools.

This strategy is very powerful. A good example is the Dropbox case: they grew 3900% in 15 months mainly by giving extra free space to their affiliates and referred users.

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2. Are you using lead magnets?
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Whichever is the medium you are reaching your potential subscribers, make sure to tease them properly, by giving a freebie (PDF, webinar or whatever) in exchange to their precious emails.

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3. How exactly is your free content?
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Either it is a lead magnet, blog article, video, each piece of free content you provide has 3 purposes:
1) To provide value to the prospect.
2) To establish your authority.
3) To drive prospects towards action.

Just think about the biggest immediate problem your ideal prospects might have, mapping out ONE thing they must do to solve it.

Remember to put your focus solely on that one thing, being as specific as possible. In the end, promote your paid subscription.

Then make several freebies like this covering different topics.

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4. Paid advertising
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I would recommend you to run ads targeting prospects with specific job titles and/or from specific industries etc, on LinkedIn and Facebook.

Yes, I said Facebook. I know top millionaire professionals reaching 7-figure serious clients with Facebook Ads with great success (best example I know: Frank Kern).

You can run lead-generation ads, using lead magnets as I've described above.

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5. What about YouTube?
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Besides the high search volume within YouTube, their hosted videos have a high relevance on Google searches (especially because they are own by Google).

The main difference in the YouTube strategy is that your prospect will start the interaction seeing your content rather than first giving their email to then see the content. A workaround is to talk about the subject mentioning they can download a PDF with the framework to solve the problem. So when they click on the link in your video description you're gonna collect their emails.

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6. How is your marketing automation?
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The vast majority of people who receive our marketing messages say no. That's just the human nature, no matter how skilled we are.

That's why we have to track non-converted prospects and bring them back with a smart approach.

Nowadays we have several ways of tracking prospects behaviour in order to divert them to specific funnels according to their interactions, such as: who opened or not the email, watched the webinar, watched only X% of it, downloaded or not a PDF etc.

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7. Get a qualified coach
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Just give me a call and I can coach you on any of above proven strategies, so that we can draw a marketing plan tailored to your own goals and niche.

Best regards,
Carlos.

Other providers like you answer online questions (f.ex. Quora), maintain blogs, participate in online fora (Linkedin, etc.) with the purpose of increasing visibility of their newsletter offering. Not in a "subscribe to my newsletter"-message, but just honest Q&A with a link to their newsletter in their bio.

Just promoted a seminar on Linkedin from my company page, and it gave 30 new followers of our company. Not subscriptions, mind you, but visibility must be key here, linking to a landing page, where you explain the value you create - perhaps with testimonials from your trusted subscribers.

Good luck!

The aim of any newsletter marketing is to increase the number of subscribers for the newsletter. Let us look at the following ways:
1. Include an opt-in form after each blog post: By placing an opt-in form at the bottom of each blog post you are catching the visitor at the perfect time right after they finish reading your content. If your content provided value, the visitor will be more willing to hand over his or her email address to continue engaging with your brand. If your website is built using WordPress there are several free plugins that allow you to create several customizable styles of opt-in forms and integrate them with your email marketing service. Optin Forms and WP Conversion Boxes are two great options.
2. Promote your newsletter via social media: Every business should have a social media presence, and this is a great audience to attract newsletter subscribers from. Is every single follower and fan that is socially connected to your business already subscribed to your newsletter? That is highly unlikely, making this an easy way to add new subscribers. If someone has “Liked” your Facebook page or is following your Twitter account, then there is already an established relationship. They are obviously interested in your brand, so encourage them to join your newsletter by sending out frequent posts welcoming them to subscribe by highlighting the benefits of your newsletter.
3. Run contests and giveaways: What is one thing most people cannot pass up? Something for free. It does not even have to be some outrageous giveaway in terms of monetary value. In fact, your own products or service is often the best giveaway. Create a contest and offer a free trial, free service, or free product -- and to be entered into the contest require that the individual subscribes to your newsletter and shares the contest on Twitter or Facebook. So, you gain a new subscriber and you also get additional exposure across social media, which can potentially attract more subscribers and more social promoters. The right contest can become viral quickly, delivering a huge influx of email subscribers.
4. Use an exit-intent pop-up offer: There will be some people that just don’t complete your website forms, even if they are placed right after your blog content. While aggressive, an exit pop up can help convert traffic into blog subscribers. Rather than using a pop up that fires when the page loads or after a specific period of time, opt for one that uses exit intent technology, only displaying when it detects that the visitor is about to leave. Bounce Exchange, the pioneer of converting abandoning traffic, is behind some of the most aggressive and successful exit conversion campaigns. In fact, I have witnessed enough successful campaigns run by Bounce Exchange that my company, Market Domination Media, has engaged it to create and manage campaigns designed to increase our newsletter subscribers.
5. Create Twitter lead generation cards: This is one of my favourite ways to build highly targeted email lists for our clients. Twitter lead generation cards allow you to create an offer and collect email addresses in a single click. What is the best part? You know the email address is valid because Twitter passes the email address that the user has confirmed and uses in his or her profile. Twitter ads have incredible targeting options, which allows you to only present your newsletter offer to prospects that match your target criteria. You must pay for each email collected, but for businesses that really want to grow their subscriber list fast this is a great option.

Besides if you do have any questions give me a call: https://clarity.fm/joy-brotonath