My hand and Lo's paw :)
I believe that ethical and political spending is a personal decision. Personally, I don't want animals to suffer in the service of my vanity. I think there are a lot of good-hearted people out there who might simply not be aware that animal testing still goes on to the extent that it does. Many people simply don't realize how many common and easy-to-find brands there are that do not test on animals. It's important for consumers to know so that we can make informed choices that align with our consciences.
I believe in animal rights and am appalled at the suffering of animals not just in the cosmetic industry, but in commercial farming (which is the major reason I don't eat meat). Although PETA is criticized for its tactics, I support their aggressive campaigns. I think that if the mainstreaming of compassionate treatment of animals is to be successful, it needs to be spearheaded by groups that are not afraid to be perceived as aggressive. I try to spend my money in ways that support my beliefs.
What if there's a nail polish you love and it's made by a company that tests on animals?
Fortunately, a truly unique polish is a rarity. If one brand puts out a color, odds are that at least half of the major brands are putting out either a duplicate or near-duplicate. So, let's say you're out polish-hunting, and that you want mint-green. Here are a few you might encounter: Sinful Colors Mint Apple, Revlon Jaded, Essie Mint Candy Apple, Sally Hansen Mint Sorbet, American Apparel Office. They are all comparable or virtually identical. If you had been gently and politely informed that Color Club and American Apparel do not test on animals; that Essie has been bought by L'Oreal, which does test on animals; and that the word on Sally Hansen is unclear (their website says that they don't test on animals, but their parent company does), then you could make your decision of which virtually identical nail polish to purchase based on other factors such as animal testing.
It irks me to know that there is polish out there-- beautiful polish, sparkly, pretty, holographic gorgeousness that I can't allow myself to buy because every time I looked at my painted fingernails I would imagine myself personally responsible for soft, fluffy bunnies restrained in labs. Believe me, I am fully aware of what a bummer it is to see a totally gorgeous nail polish, and realize that my conscience won't let me buy it. But I have a little cat, and I think of how well I take care of her and how much I love her, and how vulnerable she is, I don't, honestly, see the difference between her and lab animals except in the arbitrary value we place on their lives.
This will help you find duplicate products from brand to brand: It's Temptalia's Dupe List .
And here's the gold standard, the ninja warrior of animal rights, PETA: Peta's Buying Guide