I actually don't care much for coloring myself but from a business perspective bound coloring books are profitable where loose sheets are not.
Also loose sheets are typically used to drum up interest and group participation.  They're seen as more of a freebie type thing.  Transporting individual pages without crumpling them is also an issue for the buyer whereas in a bound format it's a packet and less likely to wrinkle and crumple.
But that's just my two cents.

I DO love me some Steven Universe.

I don't, but my dude is well tatted up. P:  I wish I had the spare moneys for such adventures.

Drawing glitter things is rough!  Go team sparklehorse!

Totally ripped the glossy paint off one of our walls at work, but not off the cabinet walls.  It's very hit or miss.

Is it okay if it's just a photo taken from a camera?

That's the only way anyone ever sees my art online. P:

She's so fabulously fluffy!