I think the key is localism. Even though those public service shows aired in dead hours (5-6 am Sunday, as I recall), there were many times when I arrived at the station to find a stack of messages from listeners wanting the contact info from the organization interviewed. These days, I suppose it's easy enough to Google the information you want, but with a local host interviewing local organizations, it gives people some insight and perhaps some impetus to get involved. I'm thinking specifically of a representative from a battered womens' shelter that I interviewed, and how amazed I was to realize there are a lot of women awake at 5 am on Sunday mornings. Yes, I really do think we affected peoples' lives with that one. Other examples that stand out in my mind were the interviews I did with Navy Relief, which also brought in a ton of calls, a local chapter of Vietnam vets whose main goal was to assist other vets in getting medical and addiction treatment, and a pre-Christmas, er, holiday interview with the Salvation Army about where the money goes when you drop your change into the little red buckets (a lot of folks wanted to volunteer). There was also a bit of a controversy when a representative from the local YMCA chapter opined that he thought Ritalin was an excuse for lazy parenting; I called back each and every p*ssed-off listener who left a message and eventually ended up doing another show with a local childrens' hospital in order to address ADD (it wasn't yet called ADHD) and the types of medications which were available and helpful to children with those conditions. Actually, that second interview got almost as many calls as the first one, from parents wanting to know how to find that doctor and get their kids a scrip. Kinda weird.
Again, hearing local talent speak to community representatives from these organizations can do a lot more to spark interest in those organizations than no publicity at all. I think people do like to help local causes, and sometimes you may reach someone who needs those services badly, or has a relative or friend who needs them. You always hope, anyway.
As for the carted and live-read PSAs, yeah, everybody knows driving drunk can get you and other innocents killed or maimed, and nobody wants to be lectured, but I do think they benefit the community on the whole. We always kept the Call-A-Cab PSAs in the studio during the big drinking holidays, like New Year's Eve, and people did call for that info---okay, sometimes they called the next July when the service was no longer being offered. Sigh.
There are a lot of people (some on this very board) who say that terrestrial radio is rapidly becoming something used largely by those who cannot afford alternatives. If someone is unable to afford an iPod or satellite radio, they may not have Google or the Internet handy, either. Those people are in the same boat as they've ever been in, relying upon the information sources they can get for free, and they still need to be served. In fact, more so now than ever.
Let me ask you something on a semi-related vein: do you think reading Amber Alerts really helps? Even if you come to the conclusion that it doesn't, could you ignore an Amber Alert on the air and feel good about yourself later? If the answer is "no," congratulations. You still care enough about your community to spend a couple of seconds doing anything in your power to help. That means you haven't yet sold your humanity. That's a good thing.