Optionally allow event participants to purchase tickets separately from registering. This drives increased ticket purchases by reducing the number of steps when purchasing tickets. Donors who are buying multiple tickets no longer have to fill out attendee details for every ticket before purchasing
A separate registration form means donors can optionally fill out the registration after ticket purchase or be emailed a registration form that can be required to be completed prior to the event. This would allow greater flexibility and customization on what form fields need to be answered by the attendee.
We have this issue as well. A donor may buy tickets for an entire table but not yet know who he/she will invite to join them until later.