Why is the "leads affected" total reported in the "Schedule" tab prior to send different than the total sent number on the email performance report?

[Anonymous]

It looks like the difference between "leads affected" and "Sent" is the number of hard/soft bounces and pending, but then the performance report also subtracts those same hard/soft bounces and pending from "Sent" to arrive at "Delivered".

[Anonymous]

Leads affected prior to the send is the number of leads to whom Marketo will try to send the email.
It is the to number of leads that qualify for your smart list criteria less those leads where

Unsubscribed = True

Email Invalid = True

Marketing Suspended = True

Blacklisted = True

Email Address is empty

Email suspended at in past 24 hours

The numbers in the report are the results of the email
http://community.marketo.com/MarketoArticle?id=kA050000000KypPCAS