While you may not throw salt over your shoulder when you spill some, or dread the sign of a black cat crossing your path, you may still suffer from a few sales superstitions that block sales success. Negative experiences with certain types of prospects or situations can cause you to preconceive negative outcomes in similar situations.

Conversely, very positive experiences can cause you to begin a negative thought process when those same positive conditions are not present. The result is a preconditioned mind-set that can cost you a ton of sales.

Here are three such mental blocks you want to avoid.