Petco is having a 3-Day Mix and Match Sale and are offering buy 3 cat and dog supplies and get the 4th free. Eligible items will be marked with the promo New customers get $15 off $49+ with coupon code NEWPETCO15. Some exclusions apply, see site for details. Get free shipping on most orders of $35 or more, or save on shipping by choosing free store pickup. Deal ends Saturday night.