Long-form content is hard to define, but we can consider the ideal article length of 1600 words to establish a limit.
Long-form is what powers your content efforts in terms of SEO. It's what will establish your brand. Thus, writing 200 words a day is not the end-goal: I encourage every member to create his/her own blog for all business-oriented topics and to crosspost 200WaD content using the canonical link feature.
200WaD is not optimized to power your brand, it's meant to empower you as an individual by helping you get into a consistent writing habit to improve.
However, you can use this website to create long-form content consistently thanks to the "Keep on Writing" feature.
Each time you publish a post, a button appears at the bottom of your article: the "Keep on Writing" call to action. Once you hit it, it allows you to expand your initial article by at least 200 words and to publish the longer content as a separate entity. Repeat the process for a few days, and you obtain a long-form content!
This feature is simple in appearance, but it hides a powerful method: modular incremental writing. It encourages you to think of long-form content as a set of modular pieces put together over several iterations. It's no coincidence a paragraph has an ideal length of 100-200 words.
I don't see many members using it. Give it a try and let me know what you think!