TEXT OF INTERVIEW

Kai Ryssdal: The place to be for live music this week is Austin, Texas, and the South by Southwest Festival. More bands there than you can shake a stick at. But South by Southwest has also become something of a hotbed for new social media companies. Twitter was the new, new thing a couple of years ago. This year, it's something called Foursquare. Caroline McCarthy is with CNET News. Caroline, it's good to have you with us.

Caroline McCarthy: Good to be here.

Ryssdal: All right, for the uninitiated what is this thing Foursquare?

MCCARTHY: There are a lot very sort of lengthy terms for this genre of application. It's a mobile social networking application, it's a location-based social networking application. Or it's a geolocation service. Basically what it is is it's a way for you to broadcast your location.

Ryssdal: And just for the heck of it, because I know he's actually on Foursquare, I've punched up John Carney, our friend from Clusterstock who is with us in the afternoons on Fridays. And basically it lists this whole thing of where he's been, and what he does, and how many times he's been out. It's just a way to literally, as you said, let people know where you are.

MCCARTHY: Pretty much, and there were other companies that were doing the same sort of thing and oftentimes they pitched it as a way to meet new people based on where your location was. And that creeps people out. So I think Foursquare and a couple of close rivals that it has are finally figuring out a way that they can make these geolocation apps something that the mass market will use.

Ryssdal: Yeah, I should probably say that Carney has yet to friend me back on Foursquare. So I can't tell you exactly where he is right now, but you know, you get the basic picture.

MCCARTHY: Well, you know, I am friends with him on Foursquare, and if I see where he's going out tonight I can go there, and I can ask him why he hasn't approved your friend request.

Ryssdal: That would be great. So other than letting your friends know where you are though, it obviously has implications for people who want to sell you stuff.

MCCARTHY: Exactly. This literally gives advertisers a way to fine tune the most precise demographic that they possibly can. So let's say I'm someone who checks into a lot of bars very late at night in the East Village.

Ryssdal: Like John Carney. Oh no, I'm sorry, I'm just kidding.

MCCARTHY: Like John Carney. Then let's say I check into something on a particular street corner, Foursquare can sort of compute even without knowing any of my personal details that I am a bit of a night owl, and that I may be looking for a slice of pizza at this hour. So if the local pizzeria across the street is a Foursquare advertiser, it can say, hey, you know, I think you need a bite to eat.

Ryssdal: And that gets back to the whole creepy thing.

MCCARTHY: The thing that makes it less creepy is that it's possible for none of that personal information to actually come across, and additionally what Foursquare has done is if you want to get alerts from a particular advertiser, you have had to specifically say I want to get alerts from this. And that works for big media brands.

Ryssdal: Foursquare is small so far, way smaller than something like Twitter or Facebook.

MCCARTHY: It is very, very small.

Ryssdal: But is that where we're going here, I mean, is that the potential?

MCCARTHY: I'm not quite sure. I think that Facebook has phenomenal mass market appeal. Twitter has less mass market appeal. Foursquare, I think, has an even smaller user base because it's people who are primarily going out a lot who want to know what other people are out, who want to discover new places. I think it works phenomenally well in cities. I don't necessarily think that they will have that kind of traction in small towns or in rural areas. There's not sort of that social impulse to go out and that kind of thing.

Ryssdal: Caroline McCarthy. CNET News. Caroline, thanks a lot.

MCCARTHY: Thank you very much.

Ryssdal: Hey, you're on Foursquare, right?

MCCARTHY: Yeah, I am.

Ryssdal: All right, I'm going to look you up and you better friend me, OK? Or whatever it's called.

MCCARTHY: OK, OK.

Ryssdal: See you later.