Myspace

Myspace was the first major platform for social media.  It seems to still be a popular site for entertainers to promote and post..
Myspace had a big boost with the ability to embed video and YouTube, specifically.  Some knowledge of HTML code is important to customize your page.
There is a niche but its popularity yielded to the giant: Facebook.  My interest in Myspace was solely due to its parent company: Newscorp.