All the dogs at the Scotch-Brite pop-up were Dog Agency clients. Their contracts required them to post. Sprout wrote: “Had so much fun yesterday! Rollin’ around on the cuddle couch with @scotchbrite_3m Lint Rollers showed NYC (and mom!) just why us pets are so #WorthTheMess! #sponsored.” The post got 2,154 likes.

Ms. Edwards said that pets whose followers number in the hundreds of thousands could get $3,000 to $10,000 for each piece of content.

Some other things to know about pet influencers:

They get book deals.

They prize authenticity. “It’s quite important to us to remain authentic so we only work with brands we use,” said Stephanie Zheng, owner of Atticus (@atticusthehedgie, 77,000 followers), a hedgehog who posted about his love for Burger King Cheesy Tots.

They are passionate about charitable causes and awareness-raising campaigns, and careful not to gum up their feeds with too many ads.

And no matter how successful they get, they are only in this crazy business to make people happy.

Glee (@goldens_glee), a 6-month-old retriever puppy with 300,000 followers, may be the ultimate example of this. She was a brand of happiness before she was even a dog.