Reply and Run ?

I'd like to get some feedback from the ladies on the strange phenomenon I am consistently experiencing here. I understand that not everyone you write to will be interested and I don't have a problem with 'No Reply' at all but I find I get many initial one word replies like 'Hi' and then when they just disappear? Is this simply a ploy used to keep the reply rate up or am I being too cynical? It doesn't make any sense to indicate interest with a reply and then just ignore the follow up. Maybe I'm just very boring but I doubt you can tell from 1 short introductoy email <span class='ns ns_128533'>&nbsp;</span> What do you like to find in the initial 'ice breaker' message ? What is most likely to keep you engaged?