My evidence as to why we need this:
On CS people hoard things. Therefore we have multiples, obviously, and it would be nice to know how many you have instead of digging and digging and digging. My rainbow hoard is over 1,000 pets so when I need to find how many of one I have I must spend time digging in pages of pets to find it. Unless it's a store pet there is no guarantee its on a specific page, grouped with others of it because of December 18th. Do you feel like spending an hour digging to find how many of a themed pet you have... when it could simply tell you?
I do doubles of sets. Once I finish say the summer set, I do another one. After a while, as the pets pile into the groups (I separate them), you have to spend time checking what one set has and what the other doesn't. The problem: when you finish one you must dig through it to see what's missing as the archive is of no use. With event themed pets, bad eyes, and rushed time... everything blends. I remember in 2012 I had to literally ask what I was missing because I simply couldn't see it. This was after I spent a good hour digging in the groups. I do double sets because if I didn't I'd get bored on CS (I am going for a complete CS set, but I cannot afford the last pets I need without ruining the work I've completed. BUT if I did other sets of Halloween and such, I can save and eventually afford these pets).
Edit 8/15/16:
Another reason: accidentally trading away a pet because you thought you had multiples of it, but did not have more than one. Yes, this is an error on the member's side, but if you're like me and have hundreds, possibly a thousand+ of this breed... would you want to spend time flipping through pages?
Edit: As of 9/8/16 This has 20 supporters!
I have also added a poll, so add +20 "Yes" answers to the current poll!
- for this. 
