German publisher Fishlabs has inked a deal with Smaato to launch ad-funded versions of its mobile games.

Fishlabs will be using Smaato's SOMA ad-serving platform, and its first game to support it will be Galaxy on Fire 2, the sequel to one of the publisher's most popular titles.

It'll be a flexible model though. The game will be launched as a free trial version from Fishlabs' own website, while also being distributed through "viral channels" (i.e. pirate sites, as explained in this interview).

The game will offer several hours of free gameplay, before users are prompted to purchase the full thing. However, in some territories, the deal with Smaato means the entire game will be ad-supported, and so free to consumers.

"Fully integrated ads are the best way to monetize from free trial versions without bothering users with complicated billing methods or copy protection," says Fishlabs boss Michael Schade.

One of the reasons Fishlabs' titles are suitable for the ad-funded treatment is that they tend to have a lot of depth, thus racking up a lot of play-hours from users.