The COVID-19 outbreak has led to drastic changes in influential media for purchasing decisions. Which media have been used more frequently after COVID-19? Do these changes differ between product types? To provide insights into these questions, we analyzed 12,000 respondents between 2018 and 2021. The results show that the influence of word-of-mouth on purchase decisions decreased after COVID-19, while the influence of social media advertising increased. We also find that the influence is moderated by product type; for example, video advertising, a subset of social media advertising shows a higher influence for search goods than for experience goods.