Of course, the "free shipping" takes a lot longer (sometimes a week longer) than even their standard shipping. If you want free shipping that takes place reliably quickly, you have to sign up for Amazon Prime, at which point free shipping is no longer free.
Prime's about what, $7 a month? Each mile I drive costs $0.20 in gas. If having Prime saves me just half an hour / 35 mi of driving a month (less than two trips to Walmart), it's cheaper than going to the store.
If you amortize it over a year, compare it to the cost of driving to a store and include the cost of free streaming videos then Prime is virtually free.
