We use these at reception to manage client appointments. They are essential, but have a tendencey to wear out much faster than older, oaktag, type dividers. Tabs need more reiforcement, we wind up taping several times (starting almost with very first use).
These are very easy to use with MS Office. Following the directions I can print the index lines for multiple items or just add one when needed. It makes it quick and easy to find the item I need at the moment. I keep extensive notes on my contacts with various businesses and refer to the notes whenever I have another contact with them. I effectively eliminates duplicates and errors. With my notes readily available, I can even tell them who my last contact was with and what they told me.