As others have covered, it's only really a problem if you are buying things you otherwise wouldn't, or paying more for things you could get cheaper elsewhere.
If that's the case but there are a few things you can get a better price on from Amazon, consider deleting you credit card info from Amazon, preloading it each month with an amount that will cover the stuff you actually want to purchase from Amazon, and then know that when you are out of Amazon credit, you are out of luck until next month. So if you spend about $40/mo on pet stuff, you get a $45 gift card. You subtract any remaining balance from the next month, so if you only spent $36, you buy $36 to get you back up to $45, and repeat.
Also, if you are a boredom shopper, find something with which you can quickly replace the urge to browse Amazon. Always have a book nearby to pick up and read, or tell yourself that when you feel the urge to Amazon, you will go for a walk. Or bake cookies or do a Sudoku puzzle or whatever you find to be a tempting, quick distraction.