In most western countries, pets are on #2 after spendings for children in households, so your bet made sense. Though, as a lot of companies, tractions wasnt big enough back then.
Today, e.g. ZooPlus is one of the biggest pet-stuff-retailers (2023 revenue 2.5billion)
I'm pretty sure that housing, cars and food are #1, #2 and #3. Your definition of household spending seems a little unconventional. If pets are household spending, surely so is food for humans?
It was a joke I suppose.
That doesn't help someone that invested in pets.com: https://en.wikipedia.org/wiki/Pets.com