Challenge related

Thank you so much for the reply ​@Jana_S , 
I wonder what this mean Free to join a challenges 
 

I am able to join challenge like this one and even able to invite people, i don’t if my setting is wrong 
 

When you look at the "challenge gallery" on the web, or "groups --> challenges" on the app and see things like your posting about "the Feed" challenge, please understand those are really paid advertisements placed by those corporations.  Commonly, companies like Le Col, Brooks and Red Bull pay Strava 30,000 USD and up for a challenge like that so notifications (ads) about your friends joining or completing the challenge are viewed by the Strava membership.    (Most of whom think they're getting an ad-free experience!)  Only an advertising agency can place one of these ads/challenges.

That differs from the group challenge you as a subscriber can create via the app.  They are "private and can only be viewed by athletes who are participating in the challenge at that time" as Strava puts it in their help article reference above by ​@Jana_S .

Both types are free. 

Thank you so much again for response and it makes so much sense for those companies to get a privilege from the platform. 
 

​@Arina To add some additional clarity, Strava provides two challenges features: Strava Challenges and Group Challenges

While Strava Challenges are public and open to everyone, Group Challenges are limited to a private group and are intended for competition/collaboration amongst up to 200 friends, family, or colleagues. Strava challenges feature public leaderboards, whereas group challenges have private leaderboards that are only visible to the challenge participants. You can find Strava Challenges on both the Strava app and website, while Group Challenges are only available in the Strava app. Finally, Strava Challenges are free for anybody to participate in, while Group Challenges require a Strava Subscription. 

I hope these details help clarify how you can interact with challenges on Strava!

Well, you’re not entirely correct there, ​@-Charles-  The bulk of the membership was excluded from this challenge: 

https://www.strava.com/challenges/4889 

You only permitted your buds to enter that one!   Let’s just have a little bit more transparency, now!