decay. The quasi-periodic enhancement corresponds to the weekend effect. The revenue of each movies increases at Saturday and Sunday. The weak peaks in the middle of the week correspond to the ladies day discount system at Wednesday that is very popular in Japan. From these figures, we found that the daily change of the revenue and the blog writing is very similar. This feature is found for all 25 movies. It means that people write their opinion on their blog with a certain probability. Figs2-3 shows us that the probability is almost constant. According to the similarity, we propose here that the number of blog-writing entry can be use as quasi-revenue for each movie. This quasi-revenue is very useful, because the quasi-revenue can be defined even before the release day. Thus, we can catch the increasing purchase intention signal using the quasi-revenue. FIG. 2: The daily data of revenue and the blog-writing entry number for the Da Vinci Code in Japanese market. The blog data are normalized to adjust the peak of the revenue at the release day. 4