If an Aldon sealer is:

1. Chosen correctly for the application goals
2. Applied as directed

It should:

• Not need to be re-applied for a very long time, if ever.
• Not peel or discolor
• Save more money from the application labor cost than the sealer cost.
• "Breathe" (not trap moisture beneath the surface)

And can also (depending on sealer type):

• Enhance natural material colors (solvent-penetrating type)
• Improve color defects in grout and/or surface material (solvent-penetrating type)
• On exteriors - eliminate freeze/thaw spalling (popping the surface) caused by exterior water entry (penetrating type)
• Stop efflorescence salts from migrating to the surface (penetrating type)
• Strengthen weak grout or surface material (solvent-penetrating type)
• Strengthen bond of grout to surfacing edge (solvent-penetrating type)
• Stop lime pops on Mexican Tile (solvent-penetrating type)
• Not change appearance at all (water-penetrating type)

And also -- look pretty!