Every business owner wants more emails on their list. More email subscribers means a bigger pool of prospects. And a bigger pool of prospects increases the likelihood of instant sales for any business.If you struggle to build an email list with classic exit popups and optin forms, here’s a better way to do it. No matter if you’re just starting with list building or you already have a list of thousands, this post can help you get higher list growth rates.What are content upgradesSo, a better way to build your list is using content upgrades on your blog. In fact, this method is one of the best ways to grow your email list.Content upgrades are like lead magnets but far more targeted. A lead magnet is basically a juicy freebie that you offer readers as an incentive to sign up to your mailing list.Content upgrades tweak the lead-magnet formula by offering post-specific incentives instead of one general PDF for your entire site.Why use content upgrades for rapid list growth?Content upgrades are more effective because they are topical. So, someone who reads a blog post through, especially when they have found the blog from the search engines, is interested in that topic. And they have a good chance of entering their email to get a PDF that is closely linked to the post topic. If you show them the added value and spark curiosity, the person will want access.Brian Dean, famous blogger and SEO expert, saw a 785% increase in opt-in rates, when he started implementing content upgrades on his Backlinko blog posts.Brian Harris of VideoFruit reports high conversion rates of 20-30%, after he added content upgrades to popular posts.It sounds like this strategy is worth trying, right? But what would you use as a content upgrade?Anything closely related to the topic can be a content upgrade and help you grow your email list faster than ever. A checklist, a cheatsheet, some advanced tips, additional resources or even the blog post as a PDF. Some people also add registration forms for evergreen webinars.Here’s a list of ideas for content upgrades to get your creative juices flowing.Because content upgrades are post-specific, you need to have the right tools to promote and deliver the PDF. A simple optin form with an autoresponder won’t do the trick. You need a tool that allows you to create different offers, place them on different blog pages, and deliver the different PDFs to people who sign up.Before we dive into the best tools you can use to grow your list with the power of content upgrades, here’s a free guide to 12 lead-getting plugins that convert cold traffic.So, these are the tools your can use to set up content upgrades on your blog.1. Thrive LeadsThrive Leads is a complete list-building plugin from Thrive Themes. Thrive themes and plugins are built for WordPress websites.This paid plugin can give your email list a boost in a whole lot of helpful ways. But since this post is about content upgrade tools, we’ll skip some of the more general features and focus on how Thrive Leads helps you deliver content upgrades.First, you can create a variety of different optin forms to entice the readers of different topics.You can place a call to action within the post content and at the bottom of the post. You can also use popups that are specific to that post. For your forms, you can use a template or create a new design from scratch using the new Thrive Architect builder.Then, Thrive Leads will automatically deliver the content upgrade via your email service provider. Rest assured that the right content will reach the right inbox.Here’s more about the process: Thrive Leads offers a large number of templates to help you build the right form fast.Once you decide on a template, you can edit it with Thrive Architect, a WordPress page builder, the successor to Thrive Content Builder.As soon as you finish up the form setup, Thrive Leads makes it simple to display the content upgrade form on the page you choose.The plugin also offers a detailed targeting feature, with which you can target your content upgrades to blog categories or posts. Additionally, with smart links you are able to display a different call to action to people who are already on your list.What about a way to manage your digital assets that will serve as content upgrades, and actually send them to your readers?That’s what Thrive Leads Asset Delivery can do for you; It lets you use a third-party email marketing service to send the content upgrade to your new subscriber. The files are stored in your WordPress media library.2. OptinMonsterOptinMonster is a cloud-based tool – it’s not a WordPress plugin like Thrive Leads.  Although it’s a standalone app, OptinMonster has a WordPress plugin that makes it easy for you to enable the list- building features on your site.To use OptinMonster’s you need a monthly subscription. The web app lets you add content upgrades to existing or new forms that you create in various ways.The downloadable PDF can be hosted anywhere you want, and the visitors will get a direct download link. Once you have the content upgrade hosted somewhere, e.g. Google Drive or your site’s media library, you can set up the forms on your blog using OptinMonster. There you also choose what happens after the user opts in.You might want to show a subscription success message that gives the person a download link. Also, you can redirect the new subscriber to a page where they can download the content upgrade. Finally, you can send the content upgrade via email. In that case, you need to set up email delivery in your email marketing software.Other helpful features that you get access to with OptinMonster include:Drag and drop form builder2-step optin formsDetailed page-level targeting so you can laser target your content upgrades to specific postsExit intent targeting, to show forms to users just before they abandon your site.3. SumoSumo is another way that marketers and bloggers can use to boost their email list building.Sumo is a set of freemium tools for WordPress that focuses on list growth. Within the Sumo suite, there is the List Builder tool, the solution you need to create content upgrades for your blog. Sumo gives you three different options when it comes to delivering content upgrades:Click Actions – Trigger a PDF request when a user clicks a download button. For example, you could have users enter their email and then click “Download” to subscribe and receive the content upgradeAutomatic Email Responder – Automatically send the content upgrade PDF as part of an autoresponder sequenceSubscribe Success Redirect – Redirect your new subscriber to a download page that lets them instantly get their content upgradeAll three ways have the same end result – your subscriber gets the PDF they requested. Content upgrades don’t need to be in a PDF format; Sumo lets you upload any type of file to deliver as a content upgrade, as long as it doesn’t exceeds 100 MB.With Sumo List Builder, you can also take advantage different features that will help you build an email list fast. For instance, you can employ multiple form types, such as popups, full-screen welcome mats, in-content forms, notification bars, and more.You can also use exit intent targeting, which means, as mentioned before, that the form will be triggered by the user’s intention to leave your site.All in all, if you’re on a small budget, Sumo gives you a flexible tool for content upgrades which you can start using at no cost. If you want to remove the Sumo branding you will have to invest in a premium plan.Read Sumo’s guide to creating content upgrades in 10 minutes and increasing your optin rates by up to 785%.Which content upgrade and list building tool is right for you?Well, it depends on your need and budget.Thrive Leads will serve you best, if you can afford it (one-time payment for one year) and as long as you want to work entirely inside WordPress. With Thrive Leads you get built-in list growth tools and a way to deliver your content upgrades, all from within your WordPress dashboard.On the other hand, if you prefer the flexibility of working in the cloud and possibly manage multiple sites, then OptinMonster might be the best fit for you. For a low monthly subscription, you can get access to OptinMonster’s content upgrade features – just remember that it won’t host your PDFs for you.And finally, if you looking to work with a free option, which will be branded, Sumo is very popular and a reliable choice for rapid list growth. If you want to remove the Sumo branding you must opt for one of the paid plans – and their plans are more pricey, compared to OptinMonster.Can’t get enough of list building tools? Download this free report to discover the 12 lead-getting plugins that convert cold traffic into warm leads and customers.