Same here - 50 pts every 23 hours, can't shift that much. For those who got 2x50 a day I can think of 2 theories:
1. They haven't hit a cap yet, maybe people like us have already hit the cap so that we can only get 50 per day regardless of activities;
2. The timing of their tweets - it seems like if their regular 50 points are received earlier in the day (late US time, early CET), and they have another chance to hit another one later in the day.