Why I am not able to download free apps from Samsung apps store?

The Samsung smart phone is an Android-powered phone classified by its manufacturer as one of the thinnest, most responsive phones in the world. With the access to the Android Market, users can even download hundreds of thousands of the available apps, many of which can even be stored on the mobile phone's microSD card instead of your mobile phone's internal memory. Storing the apps on your mobile phone's MicroSD card can free up hard drive space and then keep your mobile phone running smoothly. Power on the T-Mobile Samsung Vibrant. Select the Settings from the main menu, then the Applications. Press the Manage Applications, then just choose your application you'd like to move to the SD card. Select the gray button that says, Move to the SD Card to move the application to the microSD card. If the button is grayed out, the option is not available for that application. Wait for the app to be saved to your SD card. Once the move is complete, then Move to the SD Card button will then read Move to the mobile Phone. This is the whole process which I can tell you. I hope you liked my answer.