Millennial Media, one of the largest indies in the mobile ad serving space, came out with its  monthly sector report, this time on the travel industry. Some great insights into how brands are spending money in the travel sector, what kinds of spend, and what kinds of actions travelers are taking.

Some highlights from the report:

Travel was the number three vertical on Millenial’s platform, ranked by ad spend.

» “Booking Agents and Sites” was the leading subvertical for travel, and made up 57 percent of all travel campaigns. “Hotels, Resorts and Cruise Lines” was second, followed by “Airlines.”
» When targeting specific audiences on our platform, advertisers were 3X more likely to target business travelers than vacationers.
» 59 percent of all travel campaigns gave consumers the option to download an app as a post-click action. This was significantly higher than the overall average among all Millennial Media advertisers.

The graph below shows what’s the post-click action advertisers are asking travelers/users to do:

And of course, the requisite giant infographic to explain it all: