Tumblr
Free
Tumblr is a microblogging and social networking website.
Quora
Free
Quora is a question-and-answer site where questions are asked, answered, edited and organized by its community of users.
Viralicious
Free
Viralicious is a place to find viral posts.
Stack Exchange
Free
Stack Exchange is a network of question-and-answer websites on topics in varied fields.
Minds
Open Source
Minds is an open source social networking service.
Compare Reddit with alternatives
Compare Stack Exchange and Reddit and decide which is most suitable for you.