Here is a way to earn some United Miles for shopping online. 

Gilt runs sales to members online at up to 60% off. They offer top designer brands in a variety of categories- women, men and babies & kids as well as sales for home, food & wine, experiences/ activities and travel. In order to view the sales, you must be a member.

For signing up with Gilt:
You will earn:

• 1,500 United award miles with your first purchase of $50 or more
• Earn 5 miles per $1 spent during your first 6 months