1 INTRODUCTION  
2 THE ROBOPOL OPTICAL POLARIMETRIC MONITORING PROGRAM  
2.1 The RoboPol instrument  
2.2 The first RoboPol observing season  
2.3 Multi-band monitoring of the RoboPol sources  
3 SAMPLE SELECTION CRITERIA  
3.1 Parent Sample  
3.2 June 2013 Survey Sample  
3.3 Monitoring Sample  
4 RESULTS OF JUNE 2013 SURVEY  
4.1 Observations  
4.2 Debiasing  
4.3 Polarization properties of gamma-ray–loud vs gamma-ray–quiet blazars  
4.4 Polarization fraction vs $R$ magnitude  
4.5 Intrinsic distributions of polarization fraction  
4.6 Polarization angles  
5 SUMMARY AND DISCUSSION