You can decide on how many pages you want to have displayed, after uploading click on ‘edit’ and change the amount of previewed pages. If you do not manually change the amount of pages displayed, the system will do this automatically. As a seller of documents it might be beneficial to show more pages as most buyers base their decisions on what documents they buy from the quality of shown preview pages.
The amount of pages displayed on preview pages is relative to the size of the document, this means that:
More than 30 pages = 4 preview pages
Between 15-30 pages = 3 preview pages
Between 4-15 pages = 2 preview pages
Less than 4 pages = 1 preview page