I actually never used the Instacart app and I can care less. I do care about the Costco next day grocery delivery service, which has a transparent integration with Instacart. That is, I order on Costco.com and Instacart will deliver it next day. Costco won’t allow me to chose other vendors for delivery.

If you use Instacart app to order items from Costco the price is actually different. I guess using Costco.com I have my membership benefit.

> I actually never used the Instacart app and I can care less.

What is the meaning you are trying to convey here? Genuinely confused by this sentence.

Sorry for the confusion. What I meant is that I have never made a purchase from instacart app or from instacart.com website. Instead, I am placing online orders in costco app (and sometimes with a browser on costco.com) for grocery. Instarcart is a vendor for costco's grocery delivery. When I say I don't care about instacart, I meant I am a customer of costco for this order journey, not a customer to instacart.

I too see this phrase used and it often seems to imply the opposite meaning of what is intended. It is indeed confusing.

Generally the phrase is "I couldn't care less", meaning it is impossible to care any less than I already do.

I think "I can care less" is meant to mean "I can care less than most people do, because it doesn't matter to me".

In my experience people say "I can/could care less" when they mean to say "couldn't care less". An incorrect correction of the double negative.

Thanks for the language advice!