Airlines are increasing availability of frequent-flier award tickets, the Wall Street Journal reported this week in an article that cited improvements at Delta.

The findings came from the Switchfly Reward Seat Availability Survey, a comprehensive look at success at redeeming miles or points at the basic "saver" level. The survey found two seats available at the lowest mileage level on 77 percent of booking queries made this year, up from 74 percent last year and 72 percent in 2014, according to the Journal.

At Delta, the number of miles redeemed in 2015 was up 5.4 percent, according to the company's annual report, and the number of awards rose 6.4 percent. Karen Zachary, Managing Director – SkyMiles, said the pace is quickening: In the first quarter this year, Delta issued a record number of award tickets at 2.2 million, and the average redemption price was down 10 percent.

Delta had more than 10 sales on award tickets, discounting the number of miles needed, and marketed them “aggressively” to members via email and the airline's website, the article said. The airline has also opened up availability of saver-level seats earlier.

"We're really committed to investing in the program and making it more rewarding," Zachary told the Journal.

Delta recently started letting members buy drinks with miles in airport clubs, the WSJ noted. A bottle of Dom Perignon champagne costs 25,000. Beers and spirits range from 600 to 800 miles.

The survey made 7,000 booking queries in March asking for two seats for 280 trips at each airline on dates spread from June through October. The 10 busiest long routes and the 10 busiest medium-length routes for each airline were chosen, based on total seats offered for sale over a 12-month period.

"Overall, I think the consumer is being better served (in 2016) than the year before," Jay Sorensen, president of IdeaWorks, the consulting firm that conducted the study, told the Journal.