Update: Some offers mentioned below are no longer available. View the current offers here.We occasionally see offers for 50 miles per dollar spent on magazine subscriptions… but clothing you might actually want to own? This might be a first.Currently, a company called Stitch Fix is making a huge push on United’s MileagePlus Shopping portal, offering customers an outrageous 50 miles per dollar spent on men’s and women’s clothing.Based on TPG’s valuations, United miles are worth 1.5 cents each, so that’s a whopping 75% return — but I usually manage to get far more value out of them than that, such as on this Thai first class flight from Sydney to Bangkok, where I scored 6.62 cents per mile (a ~330% return with this Stitch Fix offer). So this has the potential to be an unbeatable deal.Now, normally I wouldn’t even bother looking at a site like Stitch Fix, unless it were offering an incredible deal. And, well, wouldn’t you know! 50 miles per dollar spent is just the offer I’m looking for.Based on a sampling of TPG employees (and the promo I see when I’m not logged into my account), it seems that this 50 miles/dollar offer is available exclusively for United co-branded cardholders. I have both the United MileagePlus Explorer Card and the United MileagePlus Explorer Business Card, so it makes sense that I’m seeing the higher bonus (compared to 30 miles/dollar for non-cardholders).If you manage to spend $600 (either through Stitch Fix or a combination of other retailers), you’ll score an extra 3,000 miles. If you spent exactly $600, you’ll end up with 33,000 miles, conservatively worth $495.But Stitch Fix isn’t your typical clothing store — you can’t see prices upfront (though you can offer guidelines) or select specific items to order. Here’s how MileagePlus Shopping describes this site:Stitch Fix is the online personal styling service (for women & men) tailored to your taste, budget and lifestyle. Fill out a Style Profile, & one of Stitch Fix’s expert stylists will hand-select five apparel, footwear and accessory items just for you. Only pay for what you keep & return the rest in a prepaid return envelope. You can receive Fixes on various cadences, or on a date that meets your needs – no subscription required.Meanwhile, the only terms and conditions state:Sign up for our daily newsletterEmail addressSign upI would like to subscribe to The Points Guy newsletters and special email promotions. The Points Guy will not share or sell your email. See privacy policy.Only eligible on new customer Stitch Fix orders. Not eligible on purchases made with coupon or discount codes that are not found on this site. Not eligible on gift cards, gift certificates or any other similar cash equivalents.So, if you’ve ordered through Stitch Fix before, you’re probably out of luck. Also, be sure to avoid adding any coupon or discount codes — I can’t imagine they’ll offer a better return than the 50 miles per dollar you’re getting here.Bottom LineSo how many miles will I earn? Honestly, I haven’t a clue. I filled out my preferences (clothing styles, sizes and so on), provided my billing and shipping info and was told to expect a delivery on August 19. So someone’s going to decide which outfits I might like, and I’ll pay for what I keep. I imagine I’ll earn 50 miles per dollar on the items I don’t send back, so I’ll certainly be more inclined to hold on to the goods this time around. This isn’t a great opportunity to “buy” miles at a cheap rate, though.Will you be earning a huge return on your Stitch Fix order?