I have the belief of the power of dua by others. The concept of true success is fundamentally about ppl talking and feeling good about you.
If you deliver good service your client will say good about you anf that is dua’. If you talk write the good words , do the good acts, it is like a tree, rooted strongly with strong stem and branches and luscious shades, fruiting for others to benefit from. That is the analogy of parable given by Allah in the Quran. That is dua and action, that a tree has to be planted in order to enjoy the fruits n shade.
The opposite is true. Take the case of out politics, If majority of voters or constituents do not give positive dua to Umno, Umno would suffer. That is dua and its manifestations