Authenticity of the platform. People tell the truth. It is unique from other platforms because it is anonymous, so people are not afraid to say what they truly feel.
User interface is good. Review collected by and hosted on G2.com.
Community can be harsh/uninclusive to new members of subreddits. When you can be anonymous, this is a consequence - people can be as mean as they want and hide under that. Other social networks, what you say is tied to your public online identity.
Reddit advertising is not as robust as Facebook. Also, I think people go to Reddit for raw, true opinions. In other words, to get past the lies of ads and sponsored posts. So there is a conflict of interest for some companies to advertise on Reddit, where that authenticity is so important.
Mobile experience leaves a lot to be desired. If you click a reddit link on the iPhone, first it takes you to the web, for which you can't view unless you go to mobile app, but then it'll take you to the app store even though you already have it downloaded. Review collected by and hosted on G2.com.
