The result of this carelessness is that at best the gum is marked, and at worst the stamp is ruined. In addition, if you make the mistake of not keeping your albums stored upright and you pile them flat, the pressure of the albums can press the stamps in mounts enough that the gum becomes smooth and you no longer have pristine MNH stamps. They may as well have been hinged for what you will get for them. Another mistake collectors make with mounts is to not leave enough room in the mount and the stamp gets its perforations crushed or the stamp becomes creased. The mounts that have a hinge-like capability can easily be crushed when you thumb through your album because they sometimes get pulled up by the opening pages and the page closes down on them before they can flop back into place.
Extra care is needed.
Some of the mounts that come in hingeless albums are not as secure at holding the stamps in place as are other types, and again extra care in handling the albums is required. I would also suggest you don't use mounts that are self-adhesive. The adhesives used in these types of mounts in the past have bled into the album page on which they were mounted. Lastly, please remember that there is no place for cellophane tape in your album. The adhesives on these tapes will run and they have the potential, over time, of ruining the looks of your album or worse ruining your stamps.