From what I understand Udemy has a fairly complex rating system that takes into consideration when a student bought a class, for how much, how far he has proceeded in it, etc. all this is taken into account in their rating system and their search system. So, its a "google" like algorithm, baby version. Thus, if free students take the course, their rating has a lower weight then someone that paid for it, and a person that paid for it has more weight than enough that has only watched one lecture.
So, I think the answer is yes. If people watch the course, give it good reviews it helps with search and placement, the more lectures they watch, the more weight these ratings have (similar to amazon's verified purchase).
But, as an author, I knew this going in about the sales 24/7, it's across the board, so I don't mind. But, as a mathematician, I wonder if they have done a proper statistical analysis that optimizes the expectation as a function of sale price and sale frequency. I find it hard to believe that having a sale 24/7 for $10 a course is the best answer. I KNOW for a fact selling video games for 20 years, that lower price works against perceived value, and in books I know that customers WILL pay higher prices for GOOD authors. At Sams, Pearson, and others I set prices for my books and my game dev series, and always charged a premium price and customers paid it. Therefore, I think Udemy could make MORE money and instructors would make MORE money if they didn't have this 24/7 80-90% discount policy.
On the other hand, maybe they DID do a study and found this algorithm to be the best. I can't imagine it's the best for instructors, but overall, it might be the best for Udemy, and it's their company
Another thing that muddies the waters is giving away 1000's of free coupons. These students didn't pay, have no skin in the game, and will never watch the whole course. It looks good at first glance, you see a course with 20,000 students, but if you watch a few videos, you quickly see how bad the course is or the language, audio, its impossible to understand. So, I am going to stick with real people, no freebees (maybe a nephew here and there), but I would rather have REAL customers, into the material, really interested in learning, rather than "collectors" that just like the idea of taking courses for free, and never actually take the course. But, maybe watch a single lecture, don't like it, then rate it down.
Andre'