First off, you don't "need" one. Second, you own an iPhone, so you should already have a general idea of what to expect from an iPad. If you feel that extending that capability to a larger screen provides a significant benefit, then go get one. For me the small screen on of iPhone is the biggest limitation to what I could do on it. The iPad has changed my day-to-day computing experience, so much so that when it comes time to replace my Laptop, I may buy an iMac instead.