Are You Allowed to Sell Fanart?


This is the best reference link I could find, so far:


basically - don't sell anything that is unoriginal content. 


      The reason I'd been looking this up is because I'm getting mixed signals on the web, pretty much everywhere. I see all these awesome fan-made products for things like Doctor Who and whatever else - on sites like Etsy, Zazzle, and Redbubble. It's all so confusing. 
        So here I am thinking, 'Is this allowed, or have they just not been caught yet?' There's a huge question mark above my head because these sites don't seem to actively enforce it. 
        I myself have had a product deleted on zazzle because Rubix made a claim against the pattern!

 I mean, really

    So, naturally, ever since then I've been cautious to tread around that area. But when I see the stuff people put up on the net, these are things that I think are really cool. Stuff I would actually consider buying because it enforces the fandom. Stuff that the copyright holders themselves would not make or ever end up making. 

    Don't these artists do the fandoms a favor though? By spreading fandom, it makes more people curious about the original work. *sigh* My head is spinning here. 

    If you're a legal guru, tell me if this this right here isn't allowed and I'll turn in for the day.