Sendbuyers.com is a buyer only traffic service that takes your link(s) and delivers buyer clicks on rotation from a daily email that goes out.
If you want to see how many clicks you are getting you need to use a link tracker. like https://roipanel.com/secret <- for example. or any tracking service.
Unlike other traffic services that send you high-volume untargeted clicks, sendbuyers.com is a low-volume but hyper targeted clicks from BUYERS only.
So whatever service you are promoting if it helps you get 1 or even 2 sales over the course of the monthly service it should easily be able to cover for what you pay for it each month (which is under $5...)
The volume of clicks you get 100% depends on how many clicks are produced from the daily email that goes out. some days you'll get clicks, some days you might not, it depends on your position in the rotator and how many clicks come in each day.