At this stage we do not have reporting on the cost information, or granular data as you describe it, but it is on the roadmap. We can report on who clicked and do a custom Marketo report that rolls up that information by account.
The way I've done this in my Marketo instance is to create 4 smart lists for Impressions, Clicks, View Through Conversions, and Click Conversions. Here is how I set up the smart list for View through conversions:
Then using those four smart lists, you can make a custom report and use the smart lists as custom columns.
Then under set up for the report I selected the "Group People by" Account name, so we can roll up all the impressions served to the account level.
Here I can see that we have 6 contacts with view through conversions under the Marketo Account.
Hope this helps!
@Jessica Cross, this is very helpful! Thank you!