It is true, PDF allows an entry into electronic distribution at low cost. However, there are many disadvantages for the user.

By using PDFs, you display on a screen what is otherwise available in printed form. Since the paper size seldom has the same size as the computer screen, the user has to change the display size and position in order to read the information relevant for him or her.

This is rather annoying when reading consecutive texts, but it is absolutely unacceptable in the case of catalogs, since this would mean you would have to jump back and forth between the illustrations and the parts lists.

The second aggravating disadvantage is that it demands additional effort to create links between text and graphics. Since these links are created with the help of mouseclick-sensitive layers, so-called overlays, these have to be edited manually each time the catalog is revised.

Therefore, an interactive and user-friendly catalog in PDF format can only be realized with an enormous effort, or it will otherwise have functional limitations.