This section covers how you can sell a sponsorship without an event registration, for example an annual sponsorship.
To achieve this, create an event, but call it something like "Gotham Chapter 2015 Sponsorship". Set the event so that it does not appear on the calendar, but do include it in search results, otherwise you won't be able to sell a sponsorship.

NOTE: Your event/sponsorship will always be listed in event manager
Set up a single registration price as zero, and then add however many sponsorships.

Although this approach is primarily for manual entry by an administrator, you can provide the link to the "event" page to potential sponsors who can purchase online if they wish.
The receipt they will receive is a generalized acknowledgement that covers either events or sponsorships.