No, you don’t. You can struggle with response rates of 0.1% or so. It is called FAILURE.
I do know of instances where the presenter does not offer a meal. These are exceptional presenters who have been doing this for years in the same market. They often draw on big lists of past attendees, as well as no-shows and people who have expressed an interest in future seminars.
For a new or revived seminar campaign, offer a meal. There seems to be a social contract between seminar marketers and investors.
The contract says, “You buy dinner, and I will give you a couple of hours of my time.”
Wine and cheese is not dinner. Dessert and coffee is not dinner. Hors d’oeuvres is not dinner. Dinner is salad, beef or chicken, dessert and coffee. Offer a no-host bar if you like.
Furthermore, do not select an ethnic restaurant. Not that I have anything personally against Mexican, Thai, Japanese, Greek, Chinese or whatever. They just do not pull well.
The restaurant you select will play a large role in your invitation success. Think: location, location, location.