This question already has an answer here:
What is preferred and more valuable for the SO community when I find an answer to my own question?
Should I wait with my answer (even when I know it is 100% correct and to the point) to give others a chance to earn some reputation points, or should I just post an answer straight away?
My main concerns are:
Not to give users a feeling that the question has been asked for 'autopromotion' purposes when author already knows the answer upfront.
Find a balance between motiving / inviting others to collaborate with valuable answers and sharing the knowledge immediately.