(Observer Pattern) PubSub on javascript

ObserverPattern.js

var publisher = {
    subscribers: {
		any: [] // Event type: subscribers
	},

	subscribe: function (fn, type) {
		type = type || 'any';
		if (typeof this.subscribers[type] === 'undefined') {
			this.subscribers[type] = [];
		}
		this.subscribers[type].push(fn);
},

	unsubscribe: function (fn, type) {
		this.visitSubscribers('unsubscribe', fn, type);
	},

	publish: function (publication, type) {
		this.visitSubscribers('publish', publication, type);
	},

	visitSubscribers: function (action, arg, type) {
		var pubtype = type || 'any',
			subscribers = this.subscribers[pubtype],
			i,
			max = subscribers.length;

		for (i = 0; i < max; i++) {
			if (action === 'publish') {
				subscribers[i](arg);
			} else {
				if (subscribers[i] === arg) {
					subscribers.splice(i, 1);
				}
			}

		}
	}
}

function makePublisher(o) {
	var i;

	for (i in publisher) {
		if (publisher.hasOwnProperty(i) && typeof publisher[i] === 'function') {
			o[i] = publisher[i];
		}
	}

	o.subscribers = { any: [] };
} 

var paper = {
	daily: function () {
		this.publish('big news today');
	},
	monthly: function () {
		this.publish('interesting analysus', 'monthly');
	}
}

makePublisher(paper);

var joe = {
	drinkCoffee: function (paper) {
		console.log('Just read' + paper);
	},
	sundayPreNap: function (monthly) {
		console.log('About to fall asleep reading this' + monthly)
	}
}

paper.subscribe(joe.drinkCoffee);
paper.subscribe(joe.sundayPreNap, 'monthly');

paper.daily();
paper.daily();
paper.monthly();