United is offering 500 United Miles if you spend $5 with Visa Checkout.
The office is valid until 30 September 2016. In order to qualify, you need to create a new Visa Checkout account, add your MileagePlus number plus your MileagePlus Visa Card to your new Visa Checkout account via this link and then purchase at least $5 within 15 days of opening your account.
If you’ve already enrolled in Visa Checkout with a MileagePlus Visa Card, you are not eligible for this offer.
Overall, a decent offer for a few minutes of your time.