Common Courtesy

As I continue my journey into random acts of kindness, I have begun to question what is a random act of kindness and what is just common courtesy and is there a difference? I decided to look up the definitions of both for comparison. The reason I am questioning the difference is because when you hear about random acts of kindness - it usually had to do with donating or something bigger than a simple hello (from my experience). Is saying good morning to someone an act of kindness or just a common courtesy and have I been going about this assignment all wrong?
In the dictionary common courtesy comes up under ettiquette which is the practices and forms prescribed by social convention or by authority. Wikipedia defined random act of kindness as a selfless act performed by a person or people wishing to either assist or cheer up an individual person or people.
It seems to me that sometimes, especially the way our society is today common courtesy now falls under random acts of kindness. There are people that I would pass by everyday and never say a word to, but now by saying good morning am I brightening up their day? While researching the definitions of both a came across a site that helps give you ideas on what to do. I also found out that tomorrow is World Kindness Day! I didn't even know this day existed! I am going to share this with my coworkers tomorrow in hope to inspire everyone to do a good deed for another. The website is http://www.randomactsofkindness.org/.
The good thing is that even though I may not be able to go volunteer everyday or donate something to the community everyday as long as I am completing acts that are meant to assist or cheer up someone else than I am headed in the right direction. I am definitely going to use that site as a resource for inspiration. I will continue with my smalls acts and make a point of planning out some bigger ones such as volunteering my time to help out the community. I can't wait to share tomorrow with the people around me and see how it unfolds. Hopefully I will have some great stories to share for my next blog.