do people really fall for this?

I was somewhat bored today, so I decided to click on one of the links in my Junk mailbox. It popped up an ad for Levitra, which is apparently an alternative to Viagra. While reading through the ad, I came across this choice statement:

The active ingredient in Levitra is much more potent than Viagra, so a patient has to take less of it, meaning it has fewer side effects.

Am I the only one who sees the flawed logic here? Clearly, if something is more potent, then taking a smaller amount of the drug should cause a similar effect to taking more of another drug which is less potent, should it not?

So I repeat: Do people really fall for this?