Bot/spam traffic = worthless, wasted bandwidth => does not convert
Traffic from real visitors with spending power, willing to buy = $$$ => does convert
The whole point of buying traffic is to sell products and services to visitors, or at least collect leads or personal data like E-mail addresses.
If you are going to sell traffic you must be able to provide stats and explain where it does come from and what visitors are looking for.
- geographic origin and distribution
- type-in vs backlinks/referals
- general patterns