I had to share my recent experience with canceling and rebooking numerous mileage tickets on United. On January 5th I booked three tickets from PBI to EWR, mileage per ticket was 28,300 for a total of 84,900 miles. Due to current generous cancellation policies, on January 19th I went back on to United and saw that the flight had gone down to 20,600 miles per person so I did instant cancellation, the mileage went right back into my account and I rebooked at 20,600 miles for a total of 61,800 miles. On January 21st I looked again and the miles per ticket had gone down to 14,000 miles for a total of 44,700 so I canceled, had the miles put back into my account and rebooked in about 3 minutes. Today, January 23rd I went to look again and the mileage was down to 11,600 per ticket. So I went and canceled my tickets and went back to book and the miles per ticket went down to 9,200 per ticket for a total of 27,600 mile. So I booked today with total savings from the original 84,900 miles of 57,300 just by going back and checking regularly.
I can honestly say I never would have thought about doing this if not for following Dan's Deals for so many years. Shout out to Dan and everyone else on the forum. Thank you!