Michael, G7VJR, author of Club Log reports:

“I’m thrilled to report to you that the half-billion mark has been passed, on 28 May 2018!

The 500 millionth QSO was uploaded by W4PG, who uploaded a QSO with ZL1BQD on 17m (FT8). Congratulations in equal parts to Robert, W4PG and Roly, ZL1BQD.

Here are the milestones I’ve recorded:
October 2009: 10 million QSOs
February 2010: 20 million QSOs
August 2010: 30 million QSOs
September 2012: 100 million QSOs
June 2013: 170 million QSOs
June 2015: 300 million QSOs
May 2018: 500 million QSOs