gistfile1.js

queue = [];

function send(data){
  queue.push(data);
  setTimeout(flush);
}

function flush(){
  if (queue.length){
    actuallyMakeRequest(queue);
    queue = [];
  }
}

The setTimeout will push flush onto the top of the timing queue. Once the current event loop tick has finished (all the js code has been executed), it will run flush. It doesn't matter how often we set the timeout, as once it get's cleared, subsequent calls will just check the length and return.

This means that code like:

analytics.identify('019mr8mf4r', {
    email   : '[email protected]',
    name    : 'Achilles',
    friends : 854
});
analytics.track('Purchased an Item', {
    revenue  : 39.95,
    shipping : '2-day'
}); 

would only make one request (I'm assuming your api supports including multiple events in a single request).