Would it though? I don't question that there would be some increase, but will it really be an explosion of consumption?

Personally, the biggest constraint on my ability to watch the large amount of films that are on my "to view" list is not the cost of the individual rentals but the availability of time in which I can actually devote to sitting down to watch a 90-, 120-, 150-, or 180-minute long film.

The ability to split up my viewings over multiple sessions helps but with the way that most online streaming rental services work for current films, 24 or 48 hour windows, I've had a number of films I've rented age-out before I've had a chance to finish them.

It really depends on the relative utility of that $5 to you. For some it would be a barrier, in that they would have free time that could have potentially been spent watching a movie but they didn't want to spend the $5. For others, the $5 is such a small amount that the barrier is time.

It's unlikely you like films enough to watch many more of them than you do now.

Not true, I enjoy them a lot but won't spend $5 to watch a twenty year old temporary digital copy when there are so many other options available. Even a brand new movie I will hem and haw about---only about two or three a year manage to pass the test.

(Not to mention the 24 hour window is problematic if you have a sleepy wife. It is not uncommon to start the movie, stop it halfway, they try to resume the next night at the same time and lose access.)

iTunes regularly has 99 cent rentals. Check it out.

Even if it's free of charge, using iTunes doesn't justify the cost.