When dating a relatively attractive broad for a period of three to eight months, then amicably break up with her. While you were in the relationship, you befriended her hot friends making them available to you once you were back in the market. Since you broke up with your girlfriend nicely she is also available to you in the future if you desire to do so.
This is called the ripple effect because like when casting a pebble into a pond causing one action to lead to many, one action (i.e. your original relationship) leads to waves of other broads available to you.
Ryan: Yo man that kid's been going out with that broad for way to damn long now.
Knox: Yea, it's gonna pay off through 'cause it's gonna cause a massive ripple effect when they break up.
...hence, the ripple effect.