Tabulka vnitřního spojení s ohledem na maximální hodnotu

SELECT  a.ID SellerID,
        a.Shop_Name,
        b.ID ProductID,
        b.pageViews,
        b.title,
        b.Price
FROM    seller a
        INNER JOIN Products b
            ON a.id = b.seller_ID
        INNER JOIN
        (
            SELECT  seller_ID, MAX(pageViews) max_view
            FROM    products
            GROUP   BY seller_ID
        ) c ON  b.seller_ID = c.seller_ID AND
                b.pageViews = c.max_View
WHERE   a.handpicked = 'Y' AND a.active = 'Y'

• Ukázka SQLFiddle

VÝSTUP

╔══════════╦═══════════╦═══════════╦═══════════╦═════════╦═══════╗
║ SELLERID ║ SHOP_NAME ║ PRODUCTID ║ PAGEVIEWS ║  TITLE  ║ PRICE ║
╠══════════╬═══════════╬═══════════╬═══════════╬═════════╬═══════╣
║        1 ║ mitienda  ║         2 ║        30 ║ bufanda ║ $25   ║
║        3 ║ new_world ║         6 ║         6 ║ ropa    ║ $13   ║
╚══════════╩═══════════╩═══════════╩═══════════╩═════════╩═══════╝