Birthdate does seem excessive, but there are some situations where they honestly do need at least your accurate name, phone number, and/or zip code. Mr. Bottlecaps works in auto parts and if you're buying a part that comes with a warranty, they'll ask for your information because they use it to look up the purchase in the event that they need to honor the warranty and exchange your part. Of course you do have the right to refuse to give your information, but make sure you don't lose that receipt. He told me that he always politely lets people know if they refuse to give the information that it's solely for their warranty purposes and just lets them know not to lose the receipt if they don't feel comfortable giving the information out.
I'm sure that wasn't the case here though, and it does seem odd that they'd ask for your information for a natural cleaning product.
This still wouldn't be an exception. There are other ways to look me up as a customer. I'm okay with providing my name, and honestly, even though it's an extremely common name (both first and last names), I've never had a problem with stores finding me that way. In one notable case, I'd needed tire service in Minnesota and my tires had been purchased in Florida. The shop in Minnesota was perfectly able to find my records even though by that time I'd changed the state my car was tagged in. Granted, he was about to give up and go get the VIN number off my car, but he was able to find me without it.
I worked for a bank for a long time and it's surprising how little bits of information can be used to commit things like account take over fraud and identity fraud.
Hence the reason it's not required, as long as the customer will have their receipt should they need to exchange the part under the warranty. Also, just to clarify, they don't need all three pieces of information - just a name or phone number will suffice for warranty purposes. I apologize for not making that more clear in my original post - it did sound like they asked for all three. There are those who don't want to give out any information at all (and that's understandable), but in that case they will have to bring the receipt, in legible condition, or else the warranty won't be honored.
That's the only time I would be willing to give out my personal information to a store, for warranty purposes, unless I had an ongoing relationship
with the store and was part of a rewards program or something (for example, a drugstore chain has used my phone number a few times to apply my points when I accidentally left my rewards card at home).
In any case, I think a simple "No, thank you," said in a polite tone, should suffice if you prefer not to give personal information out to a store (or anyone, for that matter). If pressed, stand firm.