I like pets. I especially like the cool pets that do something when you summon them, like the ones that interact with other pets. Blizzard has given us pets that are more challenging to get and some you have to pay money for as well. I don't fancy myself a pet collector, but I have a good number of them on several of my characters. They're a small aspect of WoW that's just a cool novelty item and sometimes a little entertaining. I like how Lil' KT kills critters. I love that the skunk chases around the black cat. The windrider cub/gryphon hatchling fly with you on your flying mount which is very cool. Some are rare and just for show, like various dragonlings.
The other day when Blizzard released the Lil' XT and Celestial Steed digital items on their store, I immediately went and bought them both. And by immediately I mean waited an hour in queue to pay money for something in a game. A lot of people have bitched that this is stupid, but I like my sparkle pony. It's pretty and fun to fly around with (even if they made the model a bit fat around the middle and got the run animation all wrong.) Sure it doesn't make me unique, but I'm a horse person and this is just about the only horse I can have on a Horde character that's not a skeleton. Plus it's a flying mount which is also cool. On of my guildies defended it by also pointing out that it's available to all your characters as soon as they hit 20 and it changes riding skill as you do, so you don't ever have to buy another mount again if you don't want to.
Of course the day it was available people were "bragging" in Dalaran with it over the well by the Horde bank and all over the landing platform. I'm sure this just pissed other people off and made them jealous. But it's my money right? If I get small pleasure out of something that's entirely digital then by gam, I'm gonna get it. WoW is already difficult enough to keep interesting; if this is what keeps me playing and happy, then so be it. Another guildie brought up a good point: Blizzard made a ton of money selling these things. And if that keeps my subscription cost from rising, then that's A-OK with me.