As a software engineer myself, I can tell you that building funnels from an application standpoint takes massive amounts of work. There's a great deal of coding and integration that's required here. From email systems to landing page implementations to credit card processing APIs, and everything in between, so many platforms need to "talk," that it takes the bar too high for the average marketer. 
Customers move on to Stage 5 when the sale is complete. Try sitting with your team and brainstorming upon the kinds of information these customers are going to need, as well as how you’ll provide it as part of a cohesive onboarding process. Although at this stage you don’t really need to worry about customers finding you or moving on to the next option, it’s still vital to address their needs so that they walk away feeling good about their purchase decisions.
The next step is to present potential customers with the opportunity to buy a product or procure your service. "When constructing your main front-end products and associated upsell offers, you should be engineering them with the additional mindset of . . . how will this help create more desire for the next [backend] offer [you're] going to present them with," explains Todd Brown of MarketingFunnelAutomation.com.
At Disruptive Advertising, the marketing funnel is a key part of how we approach every client’s marketing. Getting into specifics about which tactics work best under which conditions in which stages is beyond the scope of this article, but if you’d like help setting up your own marketing funnel, let me know here or in the comments. Or, for additional content, check out this blog post.

So ask yourself, is yours an expensive course that needs a lot of credibility to convince people to purchase it? Is it a free course you are launching and so may need less information and more hype and emotion? Is it a course series you are trying to encourage a commitment to? Are you one Udemy course among 100 competing courses on the same topic?   Are there obvious challenges or objections that people will have to taking your course, such as a high price or hard to achieve objectives?  Are you in a niche market and therefore need to really work hard to keep anyone remotely interested in your topic in your sales funnel?

_{Newsletters: Another effective engagement tactic is a regular newsletter. It’s typically delivered via email and focuses on delivering helpful information with a mix of incentives to encourage additional purchases. The newsletter conveys less of a salesy feel than email marketing content, so it can be a more inviting way to stay connected to your customers. Email marketing software, such as Mailchimp, can be used to execute both email marketing and newsletters.}
Blog posts: This tactic employs the principles of content marketing by offering educational articles of interest to your target audience. They’re designed to give advice or helpful insights on topics related to your business or industry, and consequently, draw consumers to your site who are interested in this information. These educational, informative posts also showcase your company’s knowledge and expertise, building your brand with the target audience.

One of the core concepts in the digital marketing industry is the sales funnel. While odd sounding at first, this single core concept can take a business from virtually non-existent and unknown to multi-million-dollar marketing machine with mass saturation, seemingly overnight. In fact, there are skilled practitioners who have built a career around implementing this single concept in business.