For me, I think internal influence is the most effect to me because internal influence basically in consumer. Internal influence is knowledge, factual information, what I know, what I interests likes or dislikes. So I think its beginning of behavior to do anything whether its purchasing needs make the consumer decision to buy product or service. If I did not need I did not purchase. its psychological need.
Example Smart Lady Savings Insurance it is internal influence to me to buy service it make me know factual information and make me A feeling that I know Purchased as a safe to be strong and has money profit come back.