This is very true, but only if it's obvious that some data is supposed to be sent to the server, e.g. a search box. In my mind this pattern didn't apply because

This is very true, but only if it's obvious that some data is supposed to be sent to the server, e.g. a search box. In my mind this pattern didn't apply because it was clear something was supposed to happen on the client, not the server, i.e. activate the timer. I presumed that causing the text box to lose focus would activate it. I know I'm wrong, I just described my dozy error caused by what I perceived to be an anti-pattern.