Two applications
On a practical level, there are two major applications:
Selling more products or services: the recommendation engine determines the ‘next best offer/action/price’ for an individual customer based on online (and offline) customer data. In this way, it can improve customer experiences while boosting sales.
Optimising and personalising content: the engine makes personalised content suggestions based on a user’s history and profile, for example, on news websites, blogs, video platforms, social media, etc.
How do you know if a recommendation engine works?
Recommendation engines are one of the most popular data science applications for good reason: their impact is undeniable, and a glance at your own behaviour on Netflix, YouTube, Amazon and the likes only confirms this. But how do you know if it works?
The most common approach is via A/B testing. In most cases, half of the visitors see content that is recommended by the engine and the other half don’t. Then, you compare how both groups reacted to the content they saw. If the recommendation engine works, there should be a significantly higher conversion rate in the study group.