Laser scanning uses the distortion of laser lines to reconstruct and object. This technology is accurate down to a maximum resolution of 0.02mm. This method is limited by the use of markers to keep the scan aligned and takes more planning to get a good model. This process is great for small to medium sized parts that require high precision.
Near Infra Red scanning takes pictures of structured infra-red light to reconstruct an object. This technology is accurate down to around 0.1mm to 2mm. This method can align the scan based on the geometry of the object and does not require markers, though they can improve results. This process is great for medium to large sized objects.
Photogrammetry is similar to NIR Scanning but uses visible light. This method is great for larger objects of for objects where a detailed texture map is required. This method is also exceptional at scanning shiny objects that other techniques might struggle with by using cross-polarized light.
Using 3D scanning can create compelling virtual models of existing products for advertising. The main advantage over normal photos is being able to digitally compose a render, instead of having to properly compose an image. This also allows you to re-render a new image whenever you want without having to get new photos.
Another advantage is that 3D scans are novel and can add interactivity to an online catalogue. Instead of presenting flat images, you can allow the end user to manipulate the view and get a better understanding of the product before purchasing. Companies like Nike have adopted this advertising method with their digital shoe customize. They basically created a mini-game where the prize is buying their product.
Using 3D scans provides a really good baseline for reverse engineering parts. It is especially useful when there are large curved surfaces or several angled faces that are hard to measure conventionally.