They work because people are looking at the same thing.
Actually, they're not. Scalpers are looking at something different than those who trade 1m charts who are looking at something different than those who trade 5m or 15m or hourly charts who are looking at something different from those who trade daily and weekly charts.
So the more important question is who do you want to trade with? Scalpers who are looking at the last swing low on a tick chart or T&S display? Or longer-term traders who are focused on the previous day's/week's low and high?
