Inpulse? EasyPay? I'm confused.

I was just at the Verizon Wireless website and the phone I am thinking about getting is the Samsung SCH-u740pp (prepaid).

It took me a while to understand how their prepay plans work but what I couldn't find out is how much it costs to use VZ Navigator. I know you have to download the application which probably costs around $10 but what do they actually charge to use it...? Is the cost per day, per use or what?

Also, I know you can download music to the phone but can you download actual music videos and if so what is the cost per video?

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