Since we adopted Fluentd, our services have acquired to integrate collecting various structured events and log data. It is not only for collecting logs, it could preprocess logs with many swiss-army knife plugins to make it easy to analyze them. Also we could easily to create input/output plugins as needed.
Fluentd has been worked in our business to help day-by-day data driven development for our Growth Hacker. Therefore, I felt Fluentd is revolutionary log collection tool I have ever seen.