The reference is about the “spiritual” gratification some (most in my experience) get from helping others – it is something that is often overlooked as it can be seen as “non-commercial”.

There are some great quotes about this in literature – one of my favourites is the Chinese Proverb:

If you want happiness for an hour — take a nap. If you want happiness for a day — go fishing. If you want happiness for a month — get married. If you want happiness for a year — inherit a fortune. If you want happiness for a lifetime — help someone else.

Churchill also said:

It is more agreeable to have the power to give than to receive.

But possibly it was Mark Twain who said it best:

The best way to cheer yourself up is to try to cheer somebody else up.

Thanks for your reply.

Kind regards,
Matthew