This post is less about pet battles themselves and more about some strange observations, and how you can use them to your advantage.
Most Pet Battle quests dont award any experience at all.
However, a few do, especially certain daily ones. This is what we will be talking about and taking advantage of.
The following 6 tamers daily quests award experience.
On Kalimdor you have:
Analynn in Western Ashenvale
Zunta near Thunder Ridge in Durotar.
Dagra the Fierce just west of the Crossroads in Northern Barrens.
In the Eastern Kingdoms you have:
Julia Stevens at the Maclure Vinyards in Elwynn Forest
Old MacDonald near the Jansen Stead in Westfall.
Lindsay south of Lakeshire in Redridge
These 6 quests can be done every day quite easily for some extra experience, however, there is an even bigger use here.
Lindsay Old MacDonald and Dagra the Fierce are special. They're quests give exp AND are account wide. The big advantage here is you can park some alts next to each one, log in, beat the quest, log out, then log onto the character you actually you want to get the experience and profit. This works great for characters like monks who you can keep safely parked in a town with their +50% exp buffs.
Another advantage for the Pet Battlers out there is that these pet battlers are all fairly low in level. You can open up with a level 1 pet swap out to a strong pet and stomp the team. Great experience for your lowbie pets and great experience for an alt!
Hope this helps some people!