Through March 31, 2012, Delta is offering a 75% bonus on the purchase or gifting of SkyMiles.
Delta ordinarily charges 3.5 cents per mile plus the 7.5% federal excise tax, for a total of 3.76 cents per mile. Through this promotion the cost is brought down to about 2.15 cents per mile. You can purchase a maximum of 60,000 miles per calendar year, so once you factor in the 75% bonus the real cap is 105,000 miles.
This is by no means a rate at which I’d buy SkyMiles just because. But if you have a specific redemption in mind, this is one way to top off an account that won’t totally break the bank. I’m waiting for them to bring back the 100% bonus on transferred miles, which was essentially an opportunity to purchase SkyMiles for roughly 1.1 cents each.
(Tip of the hat to Apu)