Trip is mentioned thousands of times in articles in Google Scholar (click here) and in the last year over 300 times (click here).  Most of these are systematic reviews and I found two new articles today, these were:

Needless to say Trip was not alone and other databases mentioned in these SRs were:

 Cochrane Library
 Google Scholar
 Web of Science

 What’s different about Trip? Size, only one paid employee (me and one day per week)!