Englishtips.org is a place where users share materials for learning English. One had scanned a book and needed the audio files, another person had the audio files but no book. Both of them found Englishtips.org and were able to complete their sets. This example from the very beginning has had a long tradition and nowadays there are more than 100.000 users - still doing the same! Besides there is a site crew with the ADMIN first of all, and helpers, called TRUSTED CONTRIBUTORS (= moderators). There are no "shop assistants" or "clerks" as some users sometimes think or ask.