With no published award-price charts to refer to, members of Delta’s SkyMiles program don’t know when award prices are higher or lower than normal. That’s because there is no baseline to use as a reference point. There is no normal. Or rather, normal is whatever Delta chooses to publish as the price for an award ticket on a particular flight.

Nevertheless, since implementing its opaque pricing scheme, Delta has on several occasions offered what were promoted as award sales. And they’re doing it again.

Offer Details

Through June 7, SkyMiles members can book award travel on more than 8,000 domestic flights between August 23 and November 16 for as few as 5,500 miles each way.

The sale prices apply to select flights, for Main Cabin and Delta Comfort seats.

Deal or No Deal

SkyMiles members will have to take Delta’s word that some award prices for some flights are discounted to some extent.

While Delta’s lack of award-pricing transparency makes it difficult to gauge the extent of a discount, if any, it’s always possible to assess the value of an award price. Simply toggle back and forth between the prices for a given flight in dollars and in miles, and divide the former by the latter. Paying 5,500 miles for a flight that could be purchased for $100, for example, amounts to getting 1.8 cents in value for every mile redeemed.

It would be easy enough for Delta to redesign its booking app to display that return-on-investment figure for every flight, saving SkyMiles members the trouble of making the calculation over and over and providing them with a clear picture of the value of their redemption options. But that would require transparency, which is precisely what Delta has chosen to excise from its loyalty program.

Reader Reality Check

How do you evaluate the worth of award redemptions?

After 20 years working in the travel industry, and almost that long writing about it, Tim Winship knows a thing or two about travel. Follow him on Twitter @twinship.

This article first appeared on SmarterTravel.com, where Tim is Editor-at-Large.