Since starting Not All Heroes over a year ago, I've found myself having a particular conversation with other serial authors, time and time again. At its core, the conversation is just a simple question: what is it that makes a serial successful? I figured that instead of rehashing my points time and time again, it would be best to spread the information out here. That way, people can read it in their leisure.
The metric of success I'm using is a nebulous mixture of financial, ranking, and general readership. For the purposes of this discussion, I'm sticking to the Top 10 of what is listed on TopWebFiction; however, there are lessons to be taken from RoyalRoadLegends as well. Some of this information comes from my own investigations, some of it comes from talking with others.
Before we begin, I'll mention that you should not look at Not All Heroes as an example for doing any of this successfully or otherwise. One, being a story following these ideas is not the story I wanted to tell. Two, I did the bulk of this work after I had already started uploading the story. As always, you should write what you want to write... but it can never hurt to know when and where you can put your fingers on the scale, no?
There are, in fact, a number of similarities among many of the biggest web serials. Ultimately, many serials acquire a greater audience more quickly than others for a simple, obvious reason: they give the audience what they want. So, the question becomes, what does the typical web serial audience member want? In my experience, that aforementioned member of the audience has a rather narrow set of desires and expectations for their serial fiction. It is also much easier to determine what they like than what they dislike. In fact, I would suggest that there is no standard set of dislikes like there are for likes -- although there are certainly things that don't seem to help a serial.
So, as mentioned, there are some similarities. Below, I've presented what I consider the three most common points across the more successful serials online. They are presented in no particular order. Any examples provided are not comprehensive.
1. Toybox Worldbuilding
This is essentially how the world is constructed and how explicitly the fictional rules are laid out. Wildbow's works, Practical Guide to Evil, and just about every LitRPG nail this aspect. I would argue that this is one of the biggest reasons behind Worm's success.
Basically, it comes down to how definitively spelled out the world is, and how simple it is for the reader to tinker with it themselves. Essentially, it's making the story into a toybox with which the reader can play within between updates. This keeps the audience engaged and keeps them thinking about your serial when they're not reading it. One could say that similar ideas are just how 'fanficable' a world is. Alternatively, to borrow another word, how toyetic it is.
For example, consider Worm and its detailed systems of power specifications and specific explanations of various processes or Practical Guide with its system of narrative-based tension and how characters acquire various titles and names.
This, of course, rewards worlds that are built to be codified in, say, a wiki. Is this a world in which it's easy for your audience to imagine mashing action figures together, so to speak? Then you've got toybox worldbuilding.
In published fiction, Brandon Sanderson does similar things. In fact, if there's one author who modelling your work on would provide maximum appeal in this space, it'd be Sanderson.
2. Gradual Progression
Think of it as equating more to an MMO loot cycle or 'leveling up' than the concept of the Hero's Journey. Since I collated these notes about a year ago, I've seen this idea in writing start to become codified under the term of 'progression fantasy.'
It could be considered a close relative of the serial 'escalation' meme. Both of them hit the same mental notch, the idea of a story always moving forwards and upwards, as if up a staircase. Characters are always acquiring things, whether those are magical items, fancy titles, new skills, mystical powers, or even just new inventive uses of their particular superpower.
3. Broken Wish Fulfillment
The interesting thing about this one is that it is sort of two things simultaneously. Unlike the other two that center on the worldbuilding and plot structure, this one reflects the protagonist. In many web serials, the protagonist is basically a blank slate, a window into the more exciting world. However, they also tend to be quite unique and often very powerful despite being underestimated.
Taylor Hebert, for example, is a character who fits this to a tee. She is a bullied everywoman who possesses incredible power, cool superhero friends, has epic battles, and ends up saving the world, where her powers are simultaneously regarded as ineffective yet extremely potent. Also, consider Zorian from Mother of Learning.
And, of course, just about every LitRPG and/or isekai does this. Essentially, this allows the reader to more easily put themselves in the shoes of the protagonist.
Those are, in my anecdotes and experiences, the big three. However, there are other, smaller things to consider. These points are more general and can be applied to serials that don't necessarily follow the aforementioned points. Again, in no particular order.
1. Consistency is key. Pick a schedule based on what you can do and stick to it. Disruptions to this schedule, even advertised ones, can slip you back down the readership hill. In my opinion, update at least twice a week. However, it is better to update once a week every week than start with two and drop to one. I think that would indicate a lack of interest or confidence. It's about habit-building.
2. When it comes to Patreons, I regard PirateAba (The Wandering Inn) as having the best one around. If I was going to start a new serial with the express purpose of making money quickly, that is the Patreon I would look at.
3. Self-promotion rarely achieves anything. Paying for promotion never does much, either. There aren't that many people looking for web fiction that isn't what they already like. This is why positive word of mouth can do wonders. Especially positive word of mouth that reaches outside the usual web serial bubbles. This leads straight into my next point...
4. Many web serials either come from an existing community or target one with laser-like precision. This community might be as narrow as a subreddit (/r/rational, /r/HFY, etc) or might be more broad, something like RoyalRoadLegends.
5. Most serial readers are reading to fill time on a commute or at lull periods in their employment or classes. They are looking for distraction and entertainment more than immersion or catharsis because they are prone to interruption and distraction, meaning their method of reading is more skimming than close engagement.
6. Therefore, building off the above, there are certain kinds of stories that may not work as well as others. To borrow how I've seen it put: no one gives a shit about characters talking about their feelings. Action and exposition can work because it allows the audience to skim and, essentially, imagine it in their own head.
7. Again, building off the previous point, this does mean that prose is not necessarily a selling point. In fact, it may be detrimental. Any work on your prose is more for your own education and development than impressing the audience. How often do we see Worm reviews that mention something along the lines of 'the start is bad but read until you get to Leviathan'? That's about 200k words, by the way.
8. A lot of the top serials are 'meta' in some way. Think tropes and subversion of them etc. Consider Practical Guide, which is basically the Evil Overlord's Guide to Evil in serial form. Worm is alternately a reconstruction or deconstruction of superheroes, depending on who you talk to. Into the Mire is maybe the most obvious exception to this.
9. I think serials have an optimal life of 3~ years. A key part of serials is following them as they develop, which means they shouldn't end too soon. But if they go on for too long, they can be seen as intimidating (too much material) or low quality (this serial has been going for three years, and it only has ten votes?) regardless of whether that's true or not. If I were to write a new serial, I'd give myself a timeline of however many updates over that three year period and sketch the whole thing out.
10. There are, of course, allowances for context. Some serials just get there first. Some serials enjoy being in the right place at the right time. But even so, it's not that simple: there are things about them that resonate.
As mentioned, this is not some magic bullet -- but it could be a key formula. At the same time, if you're just looking to figure out how to aim your serial for popularity, I feel it's accurate enough to allow you to achieve your goal. Like I always tend to say, the key is to write what you want to write. If you want to write something that does all these things, do it. If you want to write a story that aims for something different, do it. At the end of the day, writing a serial is a marathon and not a sprint. Writing what you want to write is a big help on the days where you don't want to write but, by God, you need to get that update done.
Of course, writing something new and different can be a good way of standing out. But the audience is rather focused and it likes what it likes. Don't count on novelty to help you.
At the end of the day, writing can be difficult. It's why so many people talk about writing without actually writing. Anyone who writes a serial, putting out each update to the audience, is doing better than a lot of people who claim to be writers but never move beyond worldbuilding. No matter the popularity, every serial is an achievement to be proud of.