The customer acquisition process' main steps are always the same. 

There are people, who hasn't been on our site yet, we reach them through ads, they are becoming engaged users, and in the end, the big question appears: to purchase, or not to purchase? 

Most agencies' measure conversions based on transactions, which may seem logical, but there is much more that can be done. 

We measure micro conversions, starting from the beginning of the ordering process. 

These are steps towards a macro conversion, for example, a visitor may view a product of yours, they might add it to their cart, but somehow don't make it to checkout. These are very important to measure, because,  -  e.g. in a webshop - for the first time, only 3% of the visitors make a purchase. In the case of returning visitors, it's up to 9%.  Keeping them in mind can really boost sales in the long term.