Description:This book constitutes the thoroughly refereed post-proceedings of the 8th International Workshop on Mining Web Data, WEBKDD 2006, held in Philadelphia, PA, USA in August 2006 in conjunction with the 12th ACM SIGKDD International Conference on Knowledge Discovery and Data Mining, KDD 2006. The 13 revised full papers presented together with a detailed preface went through two rounds of reviewing and improvement and were carefully selected for inclusion in the book. The enhanced papers show new technologies from areas like adaptive mining methods, stream mining algorithms, techniques for the Grid, especially flat texts, documents, pictures and streams, usability, e-commerce applications, personalization, and recommendation engines.