Most people pray out of necessity. And the words that are used in their prayer are more or less repetitive.  There is no life in their prayers. The prayers are filled with personal requests. It will have materialistic needs or wants, as well as many requests for blessings.

I believe a sincere prayer will be effective, and God will answer when it is prayed intentionally.  The intention is that it be heard by God, not for one's emotional satisfaction.  The purpose is to intercede for others.