The next time a cashier asks you for your zip code, zip your lip- unless you want more junk mail!  

Many shoppers assume stores need your zip code to complete a credit card transaction (which they don’t).  But according to privacy experts, asking for your zip is an easy way for companies to collect valuable marketing data.  Once they have it, they can use the personal info they already have from your credit card to get your phone number, mailing address and demographic details.  

Then they can send you catalogs and flyers, call your house and even sell the data for profit.  Massachusetts and California recently banned the practice, saying it violates privacy laws.