Please explain

[frkymcky]

Why is it that car rental prices are cheaper for 10 days than for 7? I have checked Alamo for a midsize from 5/1-8 and 5/1-11, it's about $100 cheaper to have the car longer. It doesn't make sense to me, could someone explain, please.

 

[seashoreCM]

They want to run a promotion for folks visiting the area for 10 days but specifically exclude a larger number of folks in the area for 7 days.

Not many business trips are for more than 5 days. A 10 day rental is just out of reach for someone on business but adding both the weekend before and the weekend after to the trip to hopefully score lower rates.