Particularly in these times, provide whatever an exhibitor prospect wants and will pay for. Don't think you can only sell floor space in 10x10 increments or 10x20 banners.
What if they only want a place to meet with their customers or good prospects? Rent them a meeting room, on or off the floor.
Do they want intimate, one-on-one exposure to only top prospects? Sell them the exclusive sponsorship to your Key Buyer reception.
Do they want to stand out? Sell them the hard-to-peddle, 9x12x15 triangle at the front corner of the show.
And the big question—should you sell sponsorships to non exhibitors? Yes. Make them an exhibitor by including a complimentary 10x10 as part of their sponsorship. If they don't want to staff this booth, lounge it with a sign "Courtesy of ...".