How many kegs are sold in the United States annually? 
Of the number of kegs sold annually, how many are purchased by
consumers for personal use (rather than restaurants etc.?
How many kegerators are sold annually?

The reasoning for this question is that I am trying to see what the
market size is for a keg cooling device that would be sold to
infrequent consumers of kegs who do not want to be a kegerator.

www.brewers.ca has some Canadian statistidsThe folks at alt.beer
http://groups.google.com/groups?q=alt.beer&ie=ISO-8859-1&hl=en would
know the answer to your question.