from the FAQ thread

How long does shopping take to credit/pend?

Shopping credits are manual credits SR must receive from the merchants and then manually import to our accounts typically on Sundays. Most shopping will credit/pend within a 7-10 business days and then will pend for 3 days if you are a SM or 21 days if you are not. Merchants have been known to hold your credits until after the item ships so please take that into account as well. There are some shopping items that will take longer to credit such as travel shopping. These items typically will credit/pend after you complete your travel.