It is no longer the case that your event's capacity has to be limited by venue size. You can set up a virtual access ticket type in addition to the "regular" ticket type(s) to come out to the venue. Selling both streaming and in-person attendance allows you to increase the revenue you can bring in from the event, and also benefits fans who may not have been able to make it in-person: I.E. fans who don't live in the area, have physical conditions that make going out difficult, or are not yet ready to do crowded events following Covid-19. Offering the virtual access option lets you market to these customers, as well.
The setup for In-Person + Virtual access is simple! Just create at least two ticket types on your event; one for in-person admission, and one for virtual access only. (Note: if you offer multiple admission levels, like VIP and General Admission, you can still have all of those for in-person admission.) Use the "#Available" setting on the attending in-person ticket type(s) to set the room capacity, and leave that setting blank for the virtual access only so that it's unlimited.
Then, after saving your event head to your account's Manage Events page, open the Select an Option dropdown on your event, and choose "Virtual Access" from the list. Go to "Grant access to the following ticket types" at the bottom of the virtual access settings and check the box for the ticket type that is streaming access only. Leave the box for any in-person ticket type unchecked. Hit the "Save" button and your virtual + in-person sales are ready to go!