I've been a deviant now for 6 years, and while I'm not one of the 'celebrities' of deviantART I did manage to find my niche after 4 years in the digital art world as a stamp artist. It took many years to find, including a small period of time where I ignored deviantART for around a year because I became so discouraged by the better artists that I felt I could never be one of them. My art is terrible. Especially when I try to draw anime characters, which sadly is my favorite, but compared to others I am like a child just learning. And I suppose I am in a way.
To many the stamp artists are not much in the way of art. We work in the confines of a small rectangle that may or may not be animate, and may or may not contain a message of any relevance to anyone. Yet over the last 2 years exploring this small niche of deviantART I've found that being a stamp artist is just as expressional as any other medium.
Stamps are a way of quickly showing others who you are, what you like, where you stand. Many deviants have walls of stamps on their page so their visitors can quickly and easily learn quite a lot about the artist in mere seconds. With a few pixels or a compressed .gif file we work to make new stamps all the time to be sure everyone can be seen quickly.
In the beginning, in the first year (or two, or four) of joining devaintART many artists may find themselves overwhelmed. "Where do I fit in? I'm no where near as good as this person. How do I get seen?" to which I did as well. I quickly learned that I am a terrible sketch artist compared to the other people on this site. Truly, too, I am not a great pixel artist compared to others, but what's great about deviantART is that it really doesn't matter if you're one of the masters or celebrities, although it must be nice, deviantART allows any one of any skill level to be seen.
Groups help I find. Being the owner of a group myself I rather enjoy seeing the art that people create to express themselves. Submit to groups and you'll find a niche that works well indeed. Worked well for me and I've been having stamper fun for 2 years now.