In recommendation systems in general, it's well known that recommending things based on recent activity far outperforms other methods (e.g. product category, past liked items, subscribed items, searched items).

For example, Hulu showed that recommending shows similar to "recently watched" rather than "watched in the past" increases CTR by 188%. In particular see the graph at the end which compares "recently watched" recommendations to other types: https://web.archive.org/web/20120130230618/http://tech.hulu....