I've used it twice now – once for a logo change and then for an email template update. You have to be very literal with the tasks you want done. I've gone back with changes a few times with each designer but they came back fast and accurate. Can't go from with the price. I think Sitepoint Group (99designs/Learnable etc.) originally modeled it off a service called Tweaky out of Australia (that's since rebranded and focused on dev/API-related tasks). I think they'll be able to scale out nicely because of the already-existing marketplace distribution with 99designs.
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