I needed traffic from the buy-side and sell-side.
On the sell side (breeders), I can just google for new customers! Many dog breeders have their own websites. I search for dog breeders and then contact them through their website (either their webform or their published emails).
On the buy-side (people looking for pets), I pay for google ads on certain keyword searches. As my website became more relevant, the cost of the ads dropped significantly and I started getting more organic searches. Getting buy-side is more difficult for me. Once you find your new pet, you don't need to visit my website anymore, so customer retention is bad... something I need to work on.