That works for things like shoes and t-shirts, but not trousers and regular shirts. It sends a bad sartorial signal to tell people just to slap on something with a decent-ish fit.
It's fine for a shop, but bad for something aimed at dressing people properly and teaching them how to do so themselves.
As a shop, it would be really cool to commission a set of really cheap "try-me-ons" in every size. You could then send these out to people for free with a prepaid return envelope - very much like online jewellers will send you a paper ring sizer for free. Just have people input what they reckon their size is, and send them that plus two sizes on either side. Make them as plain, cheap and flimsy as possible - cheaper postage, people don't order them as free clothing ('Unlimited supplies of plain white tees? Yes please!'), and if you don't get them back it doesn't cost too much.
Unfortunately, due to the differences in sizing between manufacturers, you'd probably have to be commissioning your own products for this to work, but it would be very cool for an off-the-peg suit shop, medium-high end lifestyle catalog (Land's End, etc) or something similar.
You may need fitting guides to show people how particular pieces of clothing should fit (trouser crease should break just above the shoe, shoulders should fit without bulging or sagging...) For bonus points, produce them with several different models with different body sizes - for me, having a heavier guy modelling a suit and showing how well it can disguise a gut would be a major selling point :)
Except that fit is often dependent on style. I have clothes in the same category but different styles from the same retailer where I need different sizes; heck, occasionally I've ended up having to compare different copies of the same garment in the same size, because copy variation made a worthwhile difference to fit. OK, maybe I'm a picky guy with my wardrobe ;-)
Shoes, speaking personally, would be a total non-starter online. I seem to have narrower heels than many; I'll routinely find myself searching styles to find the ones that fit me properly there rather than slipping, even if they're right elsewhere. I'm sure some others will be a little wide acrosss the toes and need just the right level of bulging across the front, or a different arch height that makes positioning of the insole's mound under the bridge or the tongue important for their comfort.
tl;dr: I can't always just buy a certain size and know that will be right. If your business model is dependent on that being possible, it won't work for me and I doubt I'm unique.
Yes, that's definitely true. Never thought of trying different instances of the same size and same style myself, actually... it's often hard enough to find a single instance!
Perhaps what we just need is rapid prototyping for clothes: "I'd like one like this, but with a more generous waist". Like bespoke tailoring but cheap and quick.
Never thought of trying different instances of the same size and same style myself, actually... it's often hard enough to find a single instance!
Agreed. It's not something I've done very often, but (for example) when you notice that the same trousers in two different waist sizes has different leg lengths in spite of what the tickets say, it's worth checking another pair sometimes.
It's fine for a shop, but bad for something aimed at dressing people properly and teaching them how to do so themselves.