hubsell decided to not allow mixing up those two data types in one campaign for the following three reasons:
Dynamic placeholders: The separation of imported vs non-imported data is based on the fact that imported cannot be controlled by us to have the same variables to use for dynamic placeholders. So in case you have a dynamic placeholder and you add data that does not have the variable on which the dynamic placeholder is based, you might send faulty emails.
Statistical analysis: hubsell data contains ~10 categorical variables that enable you to drill down on the results and analyse them for further campaigns.
Bounce rate: The bounce rate is outside our control when it comes to imported data. So for examples if you send out messages to 200 contacts, 50-50 imported and non-imported and the bounce rate of hubsell is let's say 5% and imported is 10%, the average would be 7.5%, effectively watering down the data quality, which we aim to maintain on the highest possible level.
In order to effectively target imported and non-imported prospects with your campaign, hubsell allows you to clone your campaign by clicking the ... icon on the right of your campaign and selecting copy.