I think what happens is that someone that cannot keep a constant watch may put in a high bid or a bid that may have to be their max bid and then hopes that will work for them.
@judybinder .. all that means is someone put in a bid say 5000 credits ... until you go over their top bid ..this is not a scam , click on the see more button and it will show you who is bidding but never their high bid .. this is a fun place , dont be discouraged sometimes someone really wants the item and will bid very high to make sure they get it .. good luck .. watching