I run SETI@home because it utilizes something that would otherwise be wasted. Some people don't understand that it only utilizes that which isn't being used. The thought of having a computer I installed software on find the first intelligent life besides ourselves is something that is truly exciting. I do wonder if a person finds the Cylons, Borg or other nefarious race do we get credit taken away? Or do we get carted off to Area 51 as Extraterrestrial Enemy Collaborators? :-) Either way, the power of numbers is what this is all about. Each person can't do squat on their own but together the human race will accomplish things only read about in science fiction books.
The only suggestions I have are to have some way of notifying the email of the account holder listed on the machine where SETI@home is installed if anything interesting is found. A person being able to visualize some sort of success or interesting observation is more likely to continue and do so after enlisting their friends.