If you are serious about web marketing then your best friend should be Analytics as this measures traffic, where they go, what pages they visit, what search terms were used, how long they stay and where they exist, and most importantly where they come from [lead source could be an ad on the third-party site or adwords]

It does so by placing tracking codes known as pixels strategically on your web pages, product, subscription sign-up forms, payment pages, etc. that are hidden in the source code that is invisible to the eye but engages with your visitors and enables you to see activity from your dashboard.

Setting up your analytics requires your developer to do as it’s not something you can easily do yourself.