If you're not already aware of it, Virgin America is in the process of merging with Alaska Airlines.
You can only transfer points to Alaska from Starwood (SPG), not Chase, Amex or Citi, making it a bit hard to accrue Alaska miles. Until the end of 2017 you will get 1.3 Alaska miles for every 1 Virgin America point transferred. My personal strategy with this was to sign up for the Virgin America credit card and do all my everyday spending, with the intention of eventually transferring it to Alaska for the 30% bonus. Unfortunately that credit card is no longer available to apply for but you can still earn Virgin America points other ways.
Most airlines have a shopping portal where they partner with a whole list of merchants and offer varying points per dollar spent with each one. These points are typically in addition to any points that you'll earn from whatever credit card you're using, a method known as stacking. I do all my shopping at Target this way. I sign in to my account, click the Target link that redirects me to Target's webpage and place my order. The points usually show up in my account within 40 days.
I encourage you to use a great tool, Cash Back Monitor. If you have a purchase planned you can use Cash Back Monitor to search the earn rate for each portal. See below using Target as an example.
Even though you can earn more points using British Airways' portal, I'm choosing to use Virgin America's to stockpile Alaska miles since they are harder to acquire. Remember, you can transfer Chase points to British Airways, not Alaska.
I recently decided to buy a PC Cleaning Tool, for $20, from Iolo Technologies. Virgin America was offering 9 points/$1 while Alaska was offering 20 points/$1. Alaska's higher offer made it more worthwhile to use their portal.
Virgin America Portal
$20x9pts = 180pts.
Transferred to Alaska with 30% bonus
180 pts. x 1.3 = 234 Alaska miles
Alaska Airlines Portal
$20x20pts = 400 Alaska miles
So using Cash Back Monitor to search for a better earn rate got me an extra 166 Alaska miles.
e-Rewards is a survey site where each completed survey earns you a dollar amount of e-Rewards currency. This currency can be transferred to several partners, Virgin America being one of them.
Once you've earned enough Virgin America points, you can log in to your account and convert them to Alaska miles for the 30% bonus. Keep in mind that this transfer can only go one way, so you can't get them back to Virgin if you change your mind.
I plan on holding onto my Virgin America points, until the end of 2017, just in case I need take a trip and they're the best option.