first, on making an impact:
If you want to dig a big hole, you need to stay in one place.
If you walk around town with a little shovel, you’ll just end up digging thousands of little holes, not one big one.
Call on one person ten times and you might make the sale. Call on ten people once each and you will likely get ten rejections.
second, on effectiveness:
The important thing to remember is that separate events are often separate. If you use the same ineffective approach on one thousand people, it’s not going to start working better just because you use it more often.
ht: Steve Corn