# Tariffication
# What is charged and what is not?
Personalizations are billed based on the pay for results only model.
Only calls for proven personalizations are charged.
Everything else is free.
# Personalization lifecycle and proof of personalization
Immediately after creation, personalization enters data accumulation mode.
When enough data is collected, the personalization trains its first model and transitions to model validation mode.
Once the credible interval of conversion growth becomes fully positive, the personalization becomes proven and starts being charged. Conversion growth is calculated as the increase in conversion of the personalized group relative to the control group.
You can read more about conversion growth and proof of personalization in a separate article.
# Proven personalization billing
Once the personalization becomes proven, all subsequent calls are billed.
However, to save costs, the personalization result for each user is stored for 30 days. Only the first call of the personalization is billed, which balances the cost of computational resources (and hence the price) with effectiveness.
# What is a personalization call?
A personalization call is when we retrieve the optimal option of the specified personalization for a user.
This usually happens when the user visits a page on your website that meets the display conditions. If no display conditions are set, it is considered that each page meets the display conditions.
For example, in our online store, we created the personalization "Add to cart button text". In the display conditions, we specified that the personalization only triggers on product pages.
Thus, when a user visits a product page, a personalization call is made.
# How long is the personalization result stored?
The result of each personalization is stored for each user for 30 days.
In the example above, after receiving the personalization result for the "Add to cart button text", we remember the computed optimal personalization option.
Then, if the user visits any product page again - tomorrow, in 10 or 29 days - we use the already computed optimal personalization option. Thus, during these 30 days, only the very first call will be billed, all others will be free.
# How much does a personalization call cost?
The cost of 1 proven personalization call is currently 7 kopecks * conversion growth percentage.
For example, if the current conversion growth for a personalization is 19.54%, then the personalization call will cost 19.54 * 7 / 100 = 1.367 dollars.
# Frequently asked questions
# Are old personalization calls charged after the personalization becomes proven?
No! Only new personalization calls are billed.
Moreover, if a user has a saved personalization result when it was free (not proven), we will use that saved result until the "lifetime" expires.
Accordingly, personalization calls for this user will not be billed until the old result "expires".