Delta is offering a 50 percent bonus on purchased SkyMiles through July 31, 2012. I don’t need to debate the relative value of SkyMiles versus other currencies here. We all know the deal. And we also know my advice on buying miles. Don’t do it unless you are topping off your account to take advantage of a specific award. But if you’re going to buy miles you might as well get some bonus miles too. Click here for details at Delta.com.

Edited to add: And Gary offers a pertinent comment. I scrolled to the bottom of my email and found this: “This offer is open only to the recipients of original email. Offer is not transferable and cannot be combined with any other offers. Transaction must be completed between now and July 31, 2012 to receive the 50% mileage bonus. The 50% mileage bonus offer expires at 11:59 pm CST on July 31, 2012. Offer does not apply to miles transferred under the SkyMiles Transfer Miles program. The 50% mileage bonus will post to the account within 24 hours of purchase. Offer is not transferable and cannot be combined with any other offers.”