In many regions of the world, free games backed with micro-transactions are the main source of income for mobile games publishers.

It's certainly the case in Russia, and many of the former Soviet states, where options such as operator billing and creditcard payment methods are uncommon.

Leonid Kovalev, development director, of Moscow-based studio DaSuppaStudios, explains how it has overcome such difficulties to build its successful Tankzors mobile game.

Pocket Gamer: Why do you think micro-payments works so well in the CIS market?

Leonid Kovalev: We use a try-and-buy system, because it's much better for users. If game is interesting, they will buy keys to unlock more content and buy the in-game currency. We have two kinds of payments and can use Premium SMS.

Another advantage of this system is that you can use viral marketing to distribute your games.

The main problem however is low quality of the majority Java games. This means you either need a brand or you need high quality games.

How do you design your games to encourage micro-payments?

We make sure there's good gameplay, and in the case of Tankzors we only give players five levels for free. To unlock the rest of the game, including online levels, they have to buy a key, which costs $3.

Players earn coins (the in-game currency) during the game. They use these to buy weapons from the shop, or they can use real money. It costs between 25c to $1 (a one-short code) to buy in-game currency. The ratio of keys to coins is 50:50.

However, we make sure the game is balanced so people can play without buying coins.

What statistics do you have about Tankzor's users?

The game has generated more than $1.3 million via 450,000 unique users who have paid at least once. One user can spend between the minimum price of an SMS (25c) up to $70.

The revenue is between $40,000-70,000 per month. The ARPU of the fourth and fifth Tankzors version is $5.

I think looking at our example, one can assume that proficient combinations of high quality games with micropayments will be a good driver of growth and development in other value-added service markets.

Will you be bringing any of your games to smartphones?

Our new game, Pipyaki will be completed for Java soon, and then we will port it to iPhone, PSP Minis and maybe Android.
Thanks to Leonid for his time

You can see the beta version of Pipyaki at pipyaki.ru.

You can also try Tankzors via its website or mobile site.