I can tell you without a doubt that they don’t play favorites.
If designers are getting printed over and over it’s because they are good at what they do and their products sell.
I’ve had 6 prints at DBH, and I don’t know what the number is for Teefury, probably around the same. I’m on good speaking terms with the art directors and curators of both sites. The ceo of DBH even offered me a job at one point. So based on that you could probably assume that they show me favoritism when I submit my work. Trust me, they don’t. They reject my stuff too if they don’t think it’s good enough. I’ve had a string of wins followed by a string of rejections, it happens. The fact that they like me and have printed my work before affords me nothing, and I wouldn’t have it any other way. It doesn’t matter if I’m a regular, because at the end of the day they’re businesses, so they pick what they think is going to sell, what they feel represents the brand they’ve created, and what they feel is quality.
I know it’s easier when you feel like you’re hitting a dead end to rationalize that the problem isn’t with you, but I feel that as an artist you should ALWAYS start with yourself when you’re trying to focus the blame for your failure. “What am I doing wrong?”, “What could I be doing better?” and “What are successful people doing?” are three good questions to ask yourself if you’re hitting a wall. Look more inward than outward.
I don’t know what your work looks like, so it’s impossible for me to know, but it’s possible that your work isn’t there yet and you just need to get going until you level up. Or maybe the work you’re creating is good, but it just doesn’t fit the niche of the site you’re submitting too. It might even just be technical, maybe you’re creating designs that would be to expensive/difficult to reproduce with screenprinting so they get passed over because they’re not deemed to be worth the hassle. What ever the case may be, keep working and observing. I do know people who took a long while to finally get a print.
Also, if you look through the prints this month at DBH, or any average given month, you’ll find that a good percentage of the prints are from new people. Every person who is a regular now had to get their start somewhere.