Wow, that's a huge improvement for Android Market sales figures in general. Just 3 months ago a top 5 app was getting $64/day http://news.ycombinator.com/item?id=796685 and now #14 in travel is getting as much as $156.
Android Market sales were stagnant because very few people had Android phones. The floodgates are however opening and in this coming year I expect sales will grow tremendously when the dozens of new Android phones are launched.
I think the release of the Droid phone has had a significant hand in the sales increase. I've read accounts from other Android developers who didn't make it into the ADC final round who still saw significant sales jumps around the same time due to the Droid phone release.