Hi Steven! I'm not responsible for all girls on this site I can only talk about myself. I received plenty of notes from men here. Some I answered, some I didn't. I never answer winks, never answer standard phrases like "hi! how are you?", never answer any cards (I just find them stupid). But when I see that a man has read my profile and spent his time to write me even a short nice letter, I always try to reply.
Sometimes I see from the first sight at his profile that we are not right for each other. So, why to waste time for conversations? Sometimes conversations are good from the beginning but the further you go the more you understand again that you are too different to be a couple.
I also guess that some girls correspond with several men simultaneously and when she realizes that she likes one of them better, she stops all other communication.
I quite agree with Larisa, that all women wait for more actions from men, not only words. 99% of women on this site want a real partner, a real family. 90% of men here want just chatting and a little adventure. This is sad.