Who called from 8602184486

Dear Starbucks customer, you have won a $50 Starbucks gift card! Go to www.starbuckscopromo. com (end offer? write 'OUT')valid until 4-1

I received this text on my phone:  
"Dear Starbucks customer, you have won a $50 Starbucks gift card ! Go to www.giftcardsite1.com (stop offerk, write'OUT')"

It's a scam.  If you go to the site it tries to trick you to sign up for some premium text message coupon service which bills $9.99 per month charged to your cell bill.