If you got in on the Chase United Mileage Plus card, you can now use that card and your Mileage Plus number to get 4,000 United miles with a Netflix subscription (you will be charged $7.99 per month). It will take about 1 week after signing up for your subscription for the miles to post (T & Cs say that it may take 8-10 weeks). You can cancel the subscription at anytime after the miles post. This is a great deal to give you 4,000 miles (actually, 4,007 with the Netflix subscription:) ).
Here is the link for the offer.
Here is the link for post about the United credit card.
Here is the link to sign up for a United MileagePlus number.