Imgur is essentially a parasite upon reddit which exploited and relied upon reddit's lack of native image posts. Imgur's dependency on reddit led to it trying to compete directly with it to ensure its survival without its host (Imgur is now also a place to find and comment on images), but also ensured reddit would eventually drop it, thus paradoxically also hurting its survival.
Ultimately I think Imgur is destined to the same fate as TwitPic.
Ultimately I think Imgur is destined to the same fate as TwitPic.