I mentioned elsewhere how I discovered the music of Vienna and Charlotte (and Regina Spektor and some other female singer-songwriters) on Pandora while searching for an elusive Tori Amos-like song that I had heard. (I never found the song, but who cares?)
I haven't followed up on Charlotte beyond her sampler, but she sounds more Tori-esque than Vienna to me. (Not in a bad way!) Amusingly, if you enter Vienna Teng in music-map (a very clever toy found at
http://www.music-map.com/) Charlotte pops up as her nearest neighbor.
Speaking of affinity, all of these artists are in The Ectophiles' Guide to Good Music, which is another interesting site devoted mostly to female singer-songwriters (
http://ectoguide.org/). They have a listserv too, but it's not very active.
There were a bunch of other promising artists that came out of that Pandora search that I haven't followed up yet either. That became unnecessary for Regina when she broke through on the radio shortly after.
Speaking of radio, the nearest equivalent to WXPN here in NY (WFUV, that is) has never played Charlotte according to their playlist archives. Of course, they don't play Vienna either, and even Tori gets minimal play between album releases. All of these artists are a bit too soft and down-tempo for them. From what I've heard on the 'net, XPN goes more that way than FUV does.
Finally speaking of radio, I don't subscribe to satellite, but I was listening to XM on a plane trip recently and they have a couple of stations (The Loft and Coffeehouse) where Charlotte's and Vienna's music should be at home; perhaps they have been played there. Their playlists resemble Radio Paradise online, which has played both (altho Vienna much more than Charlotte).