Three words: Focus, Focus and Focus.

What's a credit repair ad doing on a pet supply site?

The pet niche is very competitive. The pet supply niche only slightly less so. Drill deeper and find the niche within the niche within the niche...where the competition is light.

Maybe specialise in a specific breed like the Bichon Frise or some such. Nearly every article on your blog could be re-written using a particular breed as the primary part of a long-tail keyword.

Perhaps you could specialise on a particular category of pet supplies...especially if it has a good affiliate program

If you're going to concentrate on one site in one sub-sub-sub niche, Adsense is probably a poor choice. To make money with Adsense generally requires many, many sites. Stick with affiliate products if you can'ty produce a product of your own.

Yaro Starak is a professional blogger and just released
his course on blogging for big bucks.

You can hear an interview with Yaro that Willie Crawford
did a week or so ago at Willie's BlogTalkRadio page:

Listen to the interview for free here

If you want to learn to make money from blogging, this is it!

Michael

Since I am not good in selling products I prefer adsense. It depends on your choice and specialty... As long as you have traffic, both are possible..

You want to base your blog around one niche and have several things related to your niche on there. At least 3 income streams works best for me.