Through Google Offers has a Virgin America coupon that costs $50 for 50% off select tickets to or from Los Angeles or San Francisco. Book by April 30th for flights between April 11th and June 13th.
The offer is only good for flights between LAX/SFO and Chicago, Dallas, DC, Philadelphia and Seattle. That equates to about a $50 saving on that $200 round trip ticket to Seattle, or about a $150 saving on flights from Philadelphia to the West Coast.
Limit one per person.