Thanks to all for replying and so quickly! And thanks for the hearty welcome, too.
I've decided to do an experiment on an isolated website so I can simulate visitor behavior and see how Awstats reports it. The consensus seems to be that it might be visitors clicking back & refresh, and I hope this is correct.
If this is the case it might explain the other unexpected --- and disturbing --- statistic I'm trying to figure out, namely the number of times this page was the exit page. Logically, this page shouldn't be an exit page, but it was 79 times. My initial suspicion (paranoia) is that one of my competitors might be deliberately driving up my Adword cost by repeatedly clicking the Adword button, getting to the proper page, and then bailing. But if it's from people clicking back or refresh (or opening in a new window from the page in question and then closing it later), then I can understand it.
I'll post my results here in case anyone's interested. But it will be several days because it will take several steps and Awstats only reports once a day.
later!