Reviews of the service and its product unanimously give the vinyl product (which is allegedly not vinyl, but similar form of plastic) favorable assessments, though also warn to leave the inner tracks of the sides for audio less demanding of dynamic range, particularly highs. Reviewers also speak highly of the print quality of the covers, on flat-finished stock. Having worked in on-demand printing years ago, I would suppose that by now the techniques and technology had arrived at consistent near-perfection, but as to the technology for producing a single vinyl record with no master, stamper, and whatever – and no setup costs whatsoever – the company is tight-lipped. I should surmise that it's some form of laser etching on an amenable plastic disc medium, which conceivably could be done rather swiftly.
Their product has three pricing tiers, the lowest of which for a 12" LP with printed inner sleeve is $31.90. I would presume that shipping would bring it to around $40. From a sale at that price, the yield to the artist/label would be $6.38. If 10,000 copies were to sell, the yield would be over $93,000. But heck, I'd content myself with owning the only extant copy of a vinyl album by me.
I did consider that I should try this service/product out, and with my album Sigma, because I'd had an LP with two distinct "sides" in mind while producing it, and I consider the tracks' quality and flavors worthy of the medium. I also find quite coincidental that its artwork has the same colors theme as the company's website, and it would only take a spell of feelin' rich with an extra $40 to blow to convince me that such a thing means that such were meant-to-be.