Interesting piece Lucas — thank you! You are right to suggest a clap denotes recognition of performance and in the context of an article, it may not be pertinent.
How about something as simple as what YouTube uses — an upvote or a ‘badge’ with levels of achievements. In the context of an article, if you get 1,000 badges you are awarded a silver, gold badge etc. Ezinearticles uses a similar system with their authors, once they’ve submitted a certain amount of articles.