Concrete is an excellent construction material but it's not always the easiest to handle. Dumping the concrete mix from a truck directly into a form using chutes, wheelbarrows, buckets, or other placing devices can be a long slow process that leaves a finished product that is less than acceptable.
For large flat areas like roads, sidewalks, paths, and parking areas, paving machines are the most economic and efficient way to do the job. Pumping concrete is probably the way to go for many other applications. It's a very efficient and reliable means of placing concrete and very economical as well.
In many of today's applications a concrete pump is the only way of placing concrete where it's needed such as a high-rise building, or large slabs where the mixer truck chutes can't reach. Other times, the ease and speed of pumping concrete makes it the most economical and efficient way to put the mix in place.