So is it a high probability that if a chick used to be super into me and has cooled considerably and on the site we were talking on it looks like she's up talking to somebody else.
I'm assuming she's found another dude she likes talking to more than me..
I'm not positive though
I don't know what website you're talking about, but probably. Maybe she's asleep or watching a TV show though, so don't make any rash assumptions.
If you're worried about it try mixing things up with like a joke or a question or something.
And also if you find this happens often, try ask them out (of it's a dating site) while you've still got their attention.
And as always, plenty of fish in the sea, don't get too upset over these things.