Virgin America is offering up to a 70% bonus on purchased miles. (You have to log in to see the details, though I produce them below.)

I’ve seen 80% a couple of times before — though a year ago it was only for 8 hours. This time it’s valid through September 23.

With this offer — at the 70% bonus level for purchases of 5000 points or more — you’re paying about 3 cents per mile, which sounds high but Virgin America’s currency is somewhat deflated compared to most mileage programs.

Virgin America’s points are worth 2.2 cents apiece towards Virgin America travel, so it’s not a good deal to buy points and redeem them on Virgin America. But it can be a good deal to top off an account towards a specific award.

Where this does get a little bit interesting is partner redemptions. They do have partners, none of which offer out of this world value but some of which can be strategically useful, for instance:

• Emirates. New York – Dubai roundtrip on Emirates is 95,000 points plus ~ $1400 in taxes/fees. New York-Milan roundtrip on Emirates is 59,000 points and ~ $670 in taxes/fees. One-way awards are permitted.
• Virgin Atlantic. JFK-London in Virgin Upper Class is 35,000 points roundtrip plus ~ $1000 in taxes/fees.
• Virgin Australia. Los Angeles – Sydney is 80,000 points roundtrip in business class (compare to 160,000 Delta miles). Short-haul business class within Australia is quite reasonable. Six months ago Virgin America stopped adding fuel surcharges to Virgin Australia awards.
• Singapore Airlines. Short-haul regional business class on Singapore can be quite attractive, eg. Singapore – Bangkok roundtrip is 13,000 points and ~ $45 in taxes/fees
• Hawaiian. Hawaiian Airlines West Coast – Hawaii is 20,000 points roundtrip in coach. First class is 50,000 points. And no fuel surcharges apply.

Whether you should take advantage of this offer hinges on the extent to which these and similar redemptions are appealing and match your plans, in my view. But for most folks I’d advise against.

Another way to get Virgin America points is to transfer them from American Express. there’s a current transfer bonus that even lets you earn elite status.

Point purchases are processed by points.com, so to answer a common question about such transactions they do not post as travel or airfare to the credit card used for the purchase (and thus won’t earn applicable category bonuses).