Concurrent licenses for the Adobe CS suite can be maximized if computers and browsers are set to use viewer applications to open .pdf files when the full functionality of Acrobat Standard/Pro are not needed.
Sites that have bought the full version of Acrobat Pro (or Standard) as a concurrent use (shared) license from Adobe (either standalone or as part of a CS suite) should try to minimize usage of those licenses where applicable by also downloading/installing the (free) Adobe Reader and then setting up their desktops and associated browsers so that doubleclicking on a .pdf (or viewing one in a browser) opens the file via Reader (or some other program) rather than the full version of Acrobat, thus leaving the purchased software available for users who need the full Standard or Pro feature set.
How this is done will vary from operating system to operating system and from browser to browser, but at its most basic:
Setting Windows to prefer Reader:
The default path for Reader 9 is "C:Program Files\AdobeReader\9.0\Reader\AcroRd32.exe"
Setting a Windows browser (Firefox) to prefer Reader:
Setting a Macintosh to prefer Reader:
By default, .pdfs should open in Preview, but sites wanting to use Reader, or perhaps reset the default to Preview if it has got changed to Acrobat Standard or Pro, rightclick on a .pdf file and select open with/other... and browse to Preview or Adobe Reader, and make sure to check the "Always Open With" checkbox in the lower left corner.
Setting a Macintosh browser (Firefox) to prefer Reader:
When you first click the pdf the "You have chosen to open..." dialog opens, and you can use the "Open With" pulldown to select Adobe Reader and check the "do this automatically for files like this from now on" checkbox.
Once you have set this, .pdf will be added to Firefox/Preferences/Applications and will be modifiable there via the associated pulldown.