The Keitai was released in Japan before the version 2 was released.
For the keitai, there is a gotchi points sytem like the V1 and V2, though with games that in my opinion are a little more fun and the payoff is greater.
There is no shop option, but Ojitchi comes (I think it was) 3 times a day to offer one item for sale. Food items remain in the keitai's menus from generation to generation, never depleting.
The cell phone interaction option created a code system wherein you can manually input codes to purchase many different items directly. The keitai is also designed to interact with the Japanese deka tamagotchi, a large commerical tamagotci placed as a kiosk in many popular stores in Japan for access to more items.
The popularity of the deka kiosks spurred bandai to release the home version of the Deka Tamagotchi. There are fewer keitai characters than V2 characters and the game play is easier.
These are just some of the codes for the Keitai. I know some if not all work with the Akai Tamagotchi as well.
Here is a little chart of some of the things you can enter codes for and how many points they cost.