Most guys keep chatting until the girl goes offline without reading his last message.
He will wait endlessly for her to come online and read his message. He is desperate to see those blue tics for his last message 
Be different.
Be the guy who stops chatting and goes offline without reading her last message.
Be the guy who makes her think “Why don’t I see blue ticks for my last message? How dare he go offline without reading my message? Who does he think he is?!”
And THAT is the kind of guy who gets the milk 😉