[Air-l] origin of "blog"

Last week, Merriam-Webster's Collegiate Dictionary, Eleventh Edition (2003), appeared in bookstores for the first time. I was surprised not to find an entry for "blog." I thought the term was at least 5 years old. Am I right? For how long has the term been in existence among bloggers? (Webster's Tenth Edition, 1993, understandably did not include "blog"; a representative from M-W says, however, that even for the 2003 edition the term is neither old enough nor generally known enough outside bloggerhood to be included in the Eleventh. Am I justified in my astonishment, or is the rep telling it like it really is?) --Bernard