I see NFLShop.com as #1, but some of the rest appear to be spam (in some cases it's hard to tell if they are legitimate or not). I looked for legitimate sellers of NFL jerseys and by and large they have terrible SEO. I don't know how companies haven't gotten wise, but check out FinishLine.com's NFL jerseys landing page:
They have "nfl-jerseys" in the URL which is about the only redeeming thing. The page title is unrelated, which is what would show in a SERP. I clicked on the top result, a women's Ben Roethlisberger jersey and the page has nearly zero information and the images 404 (!).
http://www.finishline.com/store/shop/nfl/nfl-jerseys/_/N-2z7...
They have "nfl-jerseys" in the URL which is about the only redeeming thing. The page title is unrelated, which is what would show in a SERP. I clicked on the top result, a women's Ben Roethlisberger jersey and the page has nearly zero information and the images 404 (!).
http://www.finishline.com/store/product/reebok-womens-pittsb...
Compare that to one of the results that comes up in Google and you can see why. Great titles, URLs, the filters don't require forms.