Hi guys! I hope I’m able to contribute by bringing some of my own experience and real data to this discussion. I'm the founder of Classpert (https://classpert.com), a search and comparison site for online courses. In the last 6 months, we’ve managed to sell over 2000 courses, in 8 different languages and across 80 different countries (Udemy alone is selling around 200 courses each month through Classpert). So while it is true that price has an impact on low-income customers (especially from developing countries), even for developed countries (USA, Canada, Germany, Japan) Udemy still is leading the race in number of sales (at least if we use our database as a proxy of the market)

Much of their success stems from the fact that Udemy has by far the largest catalog of online courses on the web (something around 110k courses). And while some people may argue that this comes at a cost of providing low-quality courses it also naturally provides an extremely aggressive long-tail SEO strategy. The majority of potential customers don’t correlate e-learning platforms and quality (most of their customers are not high-profile HN users), so if you are googling for an online course chances are that Udemy will be ranked at the top (and on a global scale). This also explains why they have 10x more traffic than Pluralsight or 3x more than Coursera.

On top of that (an here is much more my personal intuition than data-based analysis), Udemy not only offers cheaper courses but also has not yet adhered to “subscription models”. Subscription models target specific users. Subscription models are awkward and feel totally unnatural to most “normal users”. Why on earth a normal user, seeking for a specific bit of knowledge will lock himself on a subscription? The subscription business model seems to work much better on B2B than B2C.