Once in a while I had a little fun with this type of thing, back when it was just starting to become a thing:
"Can I have your phone number?"
"I'll trade you, you give me the CEO's phone number and I will give you my number. I may want to call him/her to check on deals or if I have problems with the product."
"Can I have your phone number?"
"I'll trade you, you give me the CEO's phone number and I will give you my number. I may want to call him/her to check on deals or if I have problems with the product."
But generally I just politely say "No thanks"