If one were to argue by analogy one would claim that certain things share similar characteristics in common.
The following web site:
http://info-pollution.com/analogy.htm
gives a number of examples and key parts of a argument by analogy.
It gave a number of points that helped one determine if the argument was valid, strong, and relevant. The site was meant to counter argue against the statement:
“Pork, the other white meat.”
The web site points out what is weak within the argument and what is strong. It gives other analogies we can look at and think weather or not the number and quality of similarities is good.