How to optimise email marketing actions based on potential user value

Two of the key aspects in the strategic definition of a relationship marketing project are the identification of users with future projection and potential and their discrimination with respect to other users.
1) A first discrimination of users with the highest potential is based on the notion of recency.
If life cycles on the internet are shorter, it makes sense to consider segmentation based on the time elapsed between a user's action indicating their interest in our product and the current moment in which we are going to communicate with them. In other words, to identify users with a higher propensity to respond to a marketing message, we will look at those who have interacted with the brand more recently with respect to the time of the marketing action.
For example, if I send an email marketing campaign on my database and cross-reference the responses (opens, clicks and conversions) with the date on which the user opted-in, I will find that those users registered in the last 30 days get higher response rates than those registered between 30 and 60 days, and that these get higher response rates than those who registered between 60 and 90 days from the date of sending.
If I want to communicate an offer to users with a higher propensity to respond, I will do so to those with a higher recency value (understood as the closest in time).
 
(2) A second segmentation strategy is based on the origin of the register.
The more targeted the targeting, the higher the potential value of that user. This is because of the affinity between the user's interests and the advertising message that triggered the opt-in.
Suppose a user lands on the coregistration page of this image.
This page has appeared to you after a previous registration process; there was no manifest intention to search for any of these products. However, you decide to click on the Jazztel advertisement.
Let us now consider that another user has gone to Google and has actively searched for ADSL providers. He has clicked on the Jazztel advert and filled in the form below.
Which of the two users will have a higher potential value of becoming a customer? Common sense, and the facts bear this out, tells us that it will be the one who has actively sought out the product.
3. A third variable that will serve to predict the potential value of a user is the type of register.
Users whose origin is a "hard" registration form, i.e. where they have been asked for a lot of information or very sensitive information (telephone, ID) will be part of the segment of users with a high potential value. This is because the fact that they have taken time to complete the registration is indicative of a high interest in starting to engage with the brand.
4. Non-incentivised registrations.
It is common to incentivise a user's registration in exchange for valuable content, product or service (whether it is a whitepaper, prize draw, report, gift, etc.). Those users who have registered in a form without an incentive will have, compared to those who registered in an incentivised form, a higher potential value, since their interest in starting to interact with the brand will have been genuine.