I have spoken about prosperity at least once before and I have prospered myself in recent years. I don't know how much I deserve anything like it, but good things have happened regardless as I put myself in God's path.
My continued slow reading of the Book of Mormon might shed some light on some things that bring prosperity, physical and spritual.
21 Surely he hath blessed the house of Jacob, and hath been merciful unto the seed of Joseph.
22 And insomuch as the children of Lehi have kept his commandments he hath blessed them and prospered them according to his word.
As it reads, God blessed the house of Jacob (those would be the tribes of Israel) and has been merciful to the "seed of Joseph", which are more specifically the descendents of Ephriam and Menassah, the sons of Joseph. This is relevant to the writer Mormon, who is a descendent of Lehi, whose children were of both sons of the biblical Joseph. It seems that these scriptures make reference to a lineal tradition of God's followers and covenant people.
The Book of Mormon has many references that God will "prosper" his people upon the Western Hemisphere who obey him. The people of the Book of Mormon, both the righteous and the wicked, are descendents of Joseph, so blessings and mercy are due to them by heritage, if they seek such through obedience to his commandments, as in the second verse.
Blessings and mercy are not restricted to one or another of the twelve tribes of Israel: such is given to all the descendents of Jacob. Anyone who seeks out an authoritative baptism are included in the tribes of Israel and become an inheritor of these promises.
One of those promises is that we prosper according to our dilligence in keeping Christ's commandments as in verse 22.
Why not seek the prosperity that comes of being baptized into the house of Jacob and keeping the commandments of Christ?