Note, be sure to select the VISA Checkout as your payment of method during checkout. Limit one offer per customer. VISA Checkout accept any major credit or debit card [More Info]. Refer to the forum thread for additional details.
Editor's Notes & Price Research
Offer valid through August 21, 2016 or while supplies/fund last. Discount not available on gift/prepaid card purchases. Discount will be automatically applied to a qualifying purchase at Best Buy.com of $100 or more with VISA Checkout as your payment method - Discombobulated
To get the discount, click on Visa Checkout in shopping cart page (do not click on regular "Checkout").
It'll prompt you to log into or sign up for Visa Checkout, then at the Checkout page you should see a field that says "Visa Checkout Promotion -10" deducted from your total.
For more details and official terms see-