Cepro.com has an article  on using IP cameras instead of traditional closed circuit TV (CCTV) cameras.  There are reasons for choosing either IP or CCTV cameras and then more reasons to choose one model over another for a given installation.  In general, the market is moving to IP cameras for the following reasons:

More Accurate Proposals

Easier Installation

Lower Power Draw

More Flexible System Design

Opens New Markets

Avoids Expensive Analytics Software

Retrofit Solution for Analog CCTV