Sure, it’s an EC and there are good lessons within it. But watch overestimating it’s importance and blowing a bunch of smoke that they can see through. Virtually any teen/20 something we know is selling stuff on one of the many sites out there, and/or creating their own online stores. If it is a passion of his great, but it shouldn’t be considered a unique EC, agree with @milee30, it is up to him to determine/show how important it is to him on his app.