Our findings indicate a rapid turnover rate of Web pages, i.e., high rates of birth and death, coupled with an even higher rate of turnover in the hyperlinks that connect them. For pages that persist over time we found that, perhaps surprisingly, the degree of content shift as measured using TF.IDF cosine distance does not appear to be consistently correlated with the frequency of content updating. Despite this apparent noncorrelation, the rate of content shift of a given page is likely to remain consistent over time. That is, pages that change a great deal in one week will likely change by a similarly large degree in the following week. Conversely, pages that experience little change will continue to experience little change. We conclude the paper with a discussion of the potential implications of our results for the design of effective Web search engines.