Success is about the execution — did you achieve what you set out to do, regardless of the outward appreciation in numbers of attendees or monetary reward? If you did, then that event/project is/was successful and in telling the story or responding to those who ask how things went you can and should frame your story based on what you set out to do and how well you accomplished your goals.
The success of any project is based on the creator and her/his intention. I am successful because regardless of outward circumstances, I do my best, and if I am pleased with what I have created, and if only one other person finds pleasure in the work, then I met my goals.
I am successful in everything I do as always put my heart and all my efforts in all my projects.
I am successful because love feeds my creation.