The product's major flaw is precisely that they _are_ quarter-fold cards. You'll rarely find a quarter-fold at a card shop--especially not made out of heavy card stock--because they're bulky and impermanent. They're twice as thick as the more standard two-fold cards. And if you can fold them, your recipient can unfold them. This destructability fairly screams "I was made on a computer in someone's home office."

So why do so many people buy this product? I guess because the sheets are the same size as North American letter paper, they "feel" familiar. Maybe, as well, the format is a hold-over from the 1980s, when dot matrix printers reigned, and there was no other convenient way to make cards but by quad-folding. Or perhaps it's because a two-fold card in the small invitation size is rarely (if ever) available at most retail locations.

Whatever the reasons, your end results with this product will look as cheap as the card stock costs.