Weight and Size
Courier costs for transporting big bulky monitors can get ridiculous, a portable projector will fit in a backpack no problem and you can even get palm sized pico projectors that still deliver awesome brightness and impressive visuals! The Acer C200 is your ideal choice if you're short on space and need something small that can still produce a great image - it even has 4 hour battery. Offering a genuine 200 lumens of brightness from the palm of your hand the Acer C200 portable projector will help you save on space and in the exhibition environment efficient use of space is crucial.
If you're swayed by a small projector, don't be tempted to go for a bargain basement projector from amazon, as they tend to overstate their lumens rating by a factor of 10! If you're still unsure about the danger of buying on amazon check out Amazon buyer beware guide.
If you're short on space and don't have room for a TV then a short throw projector like the Pico Genie M550 Plus would be ideal for your exhibition. This LED portable projector offers a larger image at short distances compared to standard throw models, making it an incredibly versatile projector for exhibitions.
Here's a good example of a portable projector performing the job of a monitor without paying for installation or TV hire: 
Price of Ownership
With an LED projector the light source lifespan is 20,000 hours and upwards. TVs and monitors cost more in their lifetime purely by incurring larger delivery and installation costs. A portable projector is a simpler, more versatile, and more cost effective put-down-and-play option for exhibitors.
Moreover because a projector can be taken on the move, visiting other exhibitors and showing off your wares is made even easier. That hired TV monitor won't be coming back with you or to your next client sales meeting without incurring significant cost, but a portable projector offers a more cost effective choice.
Creativity and Features
The world of projectors offers a vast universe of possibilities, here are a few options:
1. Make an Interactive display- anywhere
The PIQS TT WiFi projector come with an interactive remote specially designed for gaming, presenting and drawing- and can be projected onto the wall, floor or ceiling. Why not let your visitors draw on your floors, your walls or your ceiling for a more engaging experience?
2. Paint a Mural with light
Anyone can paint a mural using a projector–no talent or experience are required! Simply create a black and white version of a high-contrast image and project it largely on a wall. Of course you'll need to find some wall space, but there's no installation cost in sight. You could even throw in some animations for added eye-catching impact.
Remember to choose an image that not only reinforces your brand, but also works well for projecting and painting.
Shoot a time-lapse video of the mural’s creation to share it online and to document how many people took part in the fun.
3. Show Off Your Assets
Gain attention by projecting eye-catching images in your booth space (try a short-throw projector for projecting in tight spots). The tone of your event will likely inform what photos you choose to display, but sources of content could include your catalog/website, demonstration videos or stills, company photos, and new product images.
This diagram by Hitachi illustrates how normal, short, and ultra-short throw distance projectors vary.
Relevant footage from a GoPro or drone, or real-time images from a remote camera can be an engaging substitute for professional photographs, as well.