Companies put out logo mats to distinct then from others. It is only not through eye-catching booths that companies invest in when joining trade shows; they also shell out money for other marketing tools like brochures, promotional literatures, giveaways and other company stuff to give out to potential buyers and clients.
Some fairs like consumer fairs rent for tents and booths with logo canopy for identification. All these are marketing strategies to draw and attract customers. When trade fairs and shows are done, the economic development of a city is also often promoted.