Producing a short video for promotional purposes does not have to be a long arduous task. In fact it doesn't necessarily involve the use of video. Below you can view a video produced in Premiere Pro. It is simply a sequence of still images with (copyright free) background music and narration added. Of course you can always add narration or indeed video, if required. However there is a lot you can do with still images, for instance, you can pan the image or zoom in giving the appearance of motion.
If you have an interesting project where you want to produce a video - let me know if you require assistance.