ClickZ notes a new report that estimates the popular bay-area-based online classifieds firm Craig's List costs the local newspaper industry about $50 million per year in job listings alone. San Francisco-based papers studiously did nothing for years as Craig's List slowly bit into their share of classifieds ads. If the new study has a weak point, it is likely its estimate that a Craig's List ad is worth on average about a $700 newspaper placement. If, alternatively, the average Craig's List ad were valued at about the equivalent of a newspaper classifieds placement (roughly $60), the Bay Area would be losing roughly $4 million in ad revenue each year in job listings, still a rather large sum.