Prices Keep Dropping; What's going on?
 

I booked a car at SFO 4 weeks out. Every time I went back to the Thrifty web site, the price had dropped a few dollars. I bring up my reservation, change the car type to the same type and get the lower price! My Ford Fusion has dropped from $45/day to $24/day. Last summer I rebooked a Ford Escape two days before my trip and saved 40% from my original booking of a month earlier.

This is bizzare...but great for me. ;) So when using Thrifty, check the rates again before your trip!

Is the market for travel so bad that they are desperate to rent their cars and just keep lowering the prices until they do? Or is this something that is common in the industry?

Economics 101 at work.

Because supply exceeds demand prices tend to drop.
During periods of high demand prices will increase.

This is exactly how a free market economy should work.
Capitalism in action.

And I just paid $1,600 for a class to tell me with over the course of 4 months.

Five or six weeks ago, I booked a car for this coming weekend, for four days at a $9.20/day base rate.

Epo57's post prompted me to recheck and, sure enough, the base rate dropped to $9.00... so I rebooked. My "Estimated Grand Total" dropped from $76.20 to $75.20, so now I can tip the shuttle driver another buck! :)

I have seen this happening as well, with a rental I originally started through AUTOSLASH (I don't work for or have any ownership in this company).. but they continue to check and rebook rates for the renter, which means I don't have to. Consistently, the rate has continued to drop the past week daily, and sometimes twice a day.