If you've got customers with junky old analog CCTV surveillance systems looking to upgrade to IP, but cost is a factor, you should take a look at 360-degree panoramic cameras. Why? Imagine one megapixel camera mounted in the center of a room that captures video in all directions. Unaltered, these cameras produce recorded video that looks like a mirror ball (i.e. a sphere of warped video). However, after image correction (de-warping the video) and splitting it in the VMS software, that one camera can produce the video capture equivalent of 4 separate cameras!
I bring this up because one of the most common objections I hear to IP video is the cost. Using such cameras can help bring the cost of an IP upgrade way down. Factor in that you only need one cable run versus four and the cost drops even more. Don't let cost be the roadblock to you selling IP cameras. New capabilities and functionality like I just described have lowered the TCO and increased the ROI of IP dramatically.