Based on my observations of other people who bought smartphones, the pros seem to be:  1.  Some people like to watch TV and movies on their phones, which they can't do on the others. 2.  It's nice to have a bigger screen than the other phones, for web browsing and movies. 3.  Many people like the phone's high definition camera, or "HD" camera.
assitant
It does? In what way?
assistant
I'm thinking about getting a smartphone, do you think it's a good idea?
user
A smartphone is one of many possible devices you could buy to be able to make and receive phone calls and access the internet.  As compared to the alternatives of a payphone, landline phone, mobile phone, or tablet, it has some pros and cons which may be better than others for you.
assistant
Okay. It sounds like a good option.
user