Why I can't write this
A CVV is the security code printed on a payment card, and it exists specifically to prove the physical card is present. "Places to buy CVV" refers to markets that sell stolen card data. Buying, selling, or using that data is card fraud in the US and most other countries, so I can't produce a buying guide, a vendor comparison, or a list of parameters and pitfalls for it.
What I can write instead
If your goal is legitimate, there are useful topics in the same neighborhood that I'm glad to write:
- How to protect your own card details online, including virtual card numbers and tokenization.
- How to spot a card-skimming or phishing page before you enter payment info.
- What to do if your card number or CVV is exposed, including freezing the card and disputing charges.
- How merchants can reduce card-not-present fraud with 3-D Secure, AVS, and velocity checks.
- How legitimate payment processors and card-issuing banks differ, and how to choose one for a business.
Tell me which of these fits your site and I'll write the full SEO piece in the same format.