Bandit Algorithms for Website Optimization

Chapter 2. Why Use Multiarmed Bandit Algorithms?

What Are We Trying to Do?

In the previous chapter, we introduced the two core concepts of exploration and exploitation. In this chapter, we want to make those concepts more concrete by explaining how they would arise in the specific context of website optimization. When we talk about "optimizing a website", we’re referring to a step-by-step process in which a web developer makes a series of changes to a website, each of which is meant to increase the success of that site. For many web developers, the most famous type of website optimization is called Search Engine Optimization (or SEO for short), a process that involves modifying a website to increase that site’s rank in search engine results. We won’t discuss SEO at all in this book, but the algorithms that we will describe can be easily applied as part of an SEO campaign in order to decide which SEO techniques work best.

Instead of focusing on SEO, or on any other sort of specific modification you could make to a website to increase its success, we’ll be describing a series of algorithms that allow you to measure the real-world value of any modifications you might make to your site(s).

But, before we can describe those algorithms, we need to make sure that we all mean the same thing when we use the word "success." From now on, we are only going to use the word "success" to describe measurable achievements like:

Traffic

Did a change increase the amount of traffic to a site’s landing ...