The emptiness of sales language

I spend a lot of time in my research reading what politicians have to say about one issue or another. There are often reasons to doubt that they are being entirely (or even at all) sincere. But generally they are at least saying something.

I just heard an ad on the radio for some medicine (I don't even remember what kind of medicine), which included, near the end, a statement along the following lines: "People who have been addicted to alcohol or other drugs may be more likely to become addicted to this product." Note the "may" — in effect, this sentence says absolutely nothing. Presumably it satisfies some legal requirement somewhere, but I can't imagine what.

I have a similar gripe with the very common sale announcements along the lines of "you could save up to 15% or more" — again, what information is being conveyed here? Taken literally, the statement is beyond meaningless: you could replace the "could" with "will" and it would still be true. I suppose the goal is to convey a particular focal point (15%) to listeners, but wouldn't there be better (less meaningless) ways to say this?