Because NFC tags are more expensive than barcodes or RFID tags (just under $1 in volume) they will make their way into high-end retail products first: Cars, electronics, consumer appliances. As more products start to include NFC tags, this will drive the price down even further. As the price goes down, NFC tags will make their way into products $20 and above (clothing, wine, shoes, Costco-sized purchases).
And then there are the phones. With almost 100 million NFC-equipped phones estimated to be shipped just over the next year and more than 1 billion predicted for the next four years, shopping, comparing, and purchasing via NFC-equipped smartphones will become commonplace.