Frappr may be a basic Google Maps mashup with a none-too-attractive interface, but it's driving good amounts of traffic (Alexa). Frappr has also become a big part of Branding 2.0 efforts - AskaNinja, CuteOverload, TWiT, Digg, Firefox, The Dawn and Drew Show and the DailyKos all use Frappr to connect their fans geographically. Unsurprisingly, they're also feeding the MySpace beast (example).
So why the huge success? Although I'd love to pin it all on MySpace, I get the sense that Frappr really took off because they nailed the early-adopter geek demographic. Not only are these people the best connected in the world, but most have their own self-publishing platforms: blogs. As always, blog widgets are key. What next? If Frappr can get more uptake with the youth demographic (read: MySpacers and Tagworlders), the service could really hit it big.
Attention Frappr Users!