The courses my Dad administrates/teaches are continuing education courses for CPA's to keep them up to date with changes in the law, etc. Every year the written materials distributed for the seminar change b/c of changes in the law and whatnot. So after a year, the material would be outdated anyway. At which point they throw away the CD.
The idea with the USB drive is that people get something with Dad's organization's logo on it that they can use frequently. They copy the info to their computer or whatever, and get to use the drive for their own purposes. Dad makes his money off of repeat business, because these folks have to have a certain number of hours of continuing education every year to get licensed by the state. But those professionals can always go to somebody else's seminars, so Dad thought the USB stick with his logo might be a nice gimmick to get folks to remember his seminar again the next year. They generally attend several seminars from different organizations throughout the year to satisfy their legal requirements, and there is a lot of competition, so getting repeat business is super important.
He himself got the idea from attending a conference where they handed out the conference materials on a USB stick, and basically told me to get on the computer and figure out how much it would cost him vs. the sixty some odd cents he pays per CD currently.