Normally we have about 25 people for weekday Mass. I advertised that we were going to celebrate Mass according to Missal of Blessed John XXIII, warned people it would take a little longer than normal.
It was the first time I celebrated the Traditional Latin Mass without an opportunity for a Novus Ordo alternative, in part because my reading of Summorum Pontificum is that the Classical Roman Mass should be a normal part of parish life and because I wanted to celebrate the feast of the Epiphany on the proper day.
I was surprised we had forty people turn up, many were younger than our normal congregation. I think people found it a deeply prayerful experience. One or two asked if we could have a sung Mass.