If you have a Virgin Atlantic Flying Club membership, you can earn more points, through their online shopping experience. These are the double miles offers:

ITunes: 6 miles/£1

Interflora: 16 miles/£1
Boden: 8 miles/£1

Ebay: 4 miles/£1

Charles Tyrwhitt: 16 miles/£1

Debehams: 8 miles/£1

Play.com: 2 miles/£1

Comet: 4 miles/£1

I want one of those.com: 20 miles/£1

Waterstones: 12 miles/£1

Apple Store: 3 miles/£1

Currys: 4 miles/£1