Since I've seen many people comparing the views and Subs they get between Tapas and Line, I'd just like to point out that Line is still massive compared to Tapas and 7 years older than it too.
Lines audience base is 17mil while Tapas (according to a newsfeed article from July this year) is 2mil.
Tapas began as a start-up in 2012, and it only has 24 people on staff (info from aforementioned newsfeed article). Meanwhile Line began in 2012 and is sponsored by Naver for all of its costs from the get go (if you were wondering how the contracted comics can still be free while they pay the creators).
That said, I post here on Tapas and not on Line for the following reasons (please note I am biased to and protective of Tapas and I acknowledge that):
Tapas has a more creator friendly environment and that is vital for the future because we need a shift in how people think of and treat creators who are professionals in their field and not just making comics for a hobby.
Tapas site is easier to use and more aesthetically pleasing to me.
I do not agree with the concept of rating free comics like on Line. It falls prey to ill will and honestly if you want to know if a comic's story is decent you just have to see the sub count and read the first 2-3 uploads.
The only comics rated on Tapas are the ones you pay for which is totally fair cause if you pay to read its reasonable to want a good story and it serves as true feedback from peeps who have paid just like reviews for print books and movies.
Tapas has a more LGBT and mature friendly stance.
(personal) My primary goal is not to rack up views and subs and eyeballs on the comics I make. I want a lifelong career in this field and Tapas is more appealing in how they're willing to form that relationship. My information is lacking here: I do not know what the relationship is like under contract with Line so if anyone can enlighten me that would be great.
(personal) In aggregate, from my personal experience and research and tendency to side with the underdog, I firmly believe that given another five years when Tapas gets to ten years old, we'll be able to see major shifts in what it means to support good webcomic stories and their Creators+Publisher.
In contrast, I have a hypothesis that once Line gets big enough to corner the market in the West, they will reach a saturation point and need to make income from the comics themselves rather than rely on Naver. This will involve having to pay to read like Tapas already has in Premium.
It's for these reason I believe Tapas has a stronger potential in the future as they help creators and help readers realize the importance to treating good stories like the quality products they are and not learning to expect things on the Internet to always be free.
Can they do better promoting the free stuff, Yeah. But like everything its a process and I personally can't stay wary and cautious all the time.
I need to put my trust in something to help my career along and right now my gut is going with Tapas.