Well, I wouldn't go so far as to say it's not worth it for most people to run NPLB as a primary project...that's entirely a matter of preference and our regulars would surely disagree. I would argue that producing a true and accurate list of prime numbers is of greater importance to society than a long-shot search for extraterrestrial life--but of course this is just my opinion and others have different preferences in project choices. As distributed computing is largely a purely hobby pursuit, a choice between projects is often less about which is more useful for society and more about which is most personally fulfilling to those running it.
Ah, okay...no problem. Just had to be sure...No, I am not who you claim I am.