Neopets, a Viacom subsidiary, has officially graduated to the increasingly familiar free-to-play, pay-for-goods format. The world of quirky virtual pets, targeted at kids, announced they will now allow users to purchase virtual currency called Neocash, which they can spend on virtual toys, clothes and special effects for their Neopets.

The new cash won't conflict with the existing currency system, called Neopoints, which kids can earn through quests and mini-games. Players can trade Neopoints for goods, but they won't be interchangeable with Neocash. Initially, the only way to score Neocash will be to purchase it via PayPal, but the company aims eventually to explore other avenues to sell the currency, such as pre-paid cards available at retail outlets.

Additionally, the availability of Neopets goods for purchase coincides with the beta of Viacom's new NC mall, which will house virtual boutiques where kids can shop for add-ons to their pet and its world. Neopets will work with Nexon, a Korean online gaming specialist, to handle the virtual transactions, as an extension of a partnership between the two announced last November.

Up until now, Viacom's revenue from Neopets came from the sale of banner advertisements on the site, which boasts over 40 million registered users around the world, and more than 12 million unique new users monthly. Viacom purchased the Neopets world in June 2005, to the tune of $160 million. Given such a large installed base and continued global expansion, the sale of virtual goods in the Neopets world may well prove to be enormously lucrative for Viacom.