Getting to the submissions for the contest seems to have changed. If I go to challenges, clicking on the banner does nothing, I have to click join or view results button. My instinct is to click the banner so I think that should be added back in. There's also some wonkyness with viewing entries themselves. Each time I want to go to the next page, I am taken to the awards tab when I should stay on the entries tab if I'm browsing.
If feel like CG trader is trying to do two things, build community and grow your library of models. Both of which I feel you guys are sort of half achieving. For the community side, I think the artists need to be showcased more. You have a few top models and top artists but it makes VERY little sense (or it's not communicated well) on how to get a top model up there. Some of the models look great and have lots of likes and views and others have maybe 19 views and no likes yet it's still a top model. Half the models on there often don't reach a quality bar that I feel reflects the kind of image you want to have selling to companies and individuals either. I think being a bit more strict in how a model becomes a top model may help. If you put the best of your best up there, you will look better to new people coming to buy. Maybe a Top models section and an up and coming section or new model section or something to separate your best from what's new.
Seems a bit off topic but it ties in with contests. There's a reason I check art station every morning. There's bad ass stuff on there and it's inspiring as hell. I don't check CG trader to get inspiration and I believe that's because of my previously stated issue. There just isn't inspiring stuff being shown up front most of the time. You show better stuff, you get more high level artists wanting to join because it's "where the pros hang out" you have pros and better stuff being shown, your customers believe you are the top site for high quality. You have that reputation, the artists you do have already will want to push harder and make higher quality work which is beneficial to everyone from the artist themselves to you as a company and you lose people trying to just make a model in a day to sell.
The contests pull people into that but I feel you need categories in tabs or something. As a 3D artist primarily, I'm not interested in 3D print challenges really unless the prize is something like a 3D printer which is amazing. Other than that, I'm interested in 3D challenges that offer packages that are beneficial to me (the substance package for the sci fi challenge is a great one because it's a tool that is being widely learned as we speak in the game industry and it made me push more to try and have something I feel would win) This again, gets you better models to sell. So I would suggest your "large prize challenges" be displayed at the top and then sub categories for others. Having to scroll through challenges to see what I'm interested in feels off. Also throwing the expired ones into a "past challenges" section is a good filter.
So the take away from what I feel here is: Show case your best art better. Still show the mid range etc. but in a "new" or "up and coming" section. Really make it all about the best things you have to sell (and in turn, your artists) on your landing page. Art station is a great example of showing awesome art. You want to feel like "CG Trader is where the pros go" and your challenges all tie directly into this community driven aspect of things.
Short notes:
Cull the entries faster - soo many entries that aren't boats, or sci fi, etc.
Show off your winners - Landing page again. Those winners are your bread and butter, sell them.
Trending sections, top model sections, top artist sections, etc. are all important to make every artist feel like they are progressing in the spotlight even if they aren't that amazing yet.
I know this isn't all challenge related but I believe it all ties together. Sorry it's so long but thank you! Also let me win the sci fi challenge :P I'm broke and need substance! :D