It's pretty self-explanatory, to me, but here goes:
There are four weekly ranksing:
1. Battle -- How much battles one of your pet wins. (Tallied by Pet)
2. Breeding Trade -- How much pets your pet/s bred in the Breeding Offers. (Tallied by Users)
3. Item Trade -- How much silver you earnt from selling your items (Tallied by User
4. Pet Trade -- How much silver you earnt from selling your pets. (Tallied by User)
As for ties, to my understanding, it goes to the Pet/User that achieved the number last,. Example: You're in 7th place, with a value of 10, and someone 'under' you reach a value of 10, you'll drop to 8th place, while that someone gets 7th place.
My Pet Sales page --
Currently have 3 extra Blueprint: Military Academy level 3
#cfddcf -- #d0e7ba