Because photos sell properties. My wife went and took about 30 shots of a $500K property that had been on the market for over a year. Within 3 weeks they had it under contract for $495K. The buyers said they had skimmed over the property a time or two in the past but when it popped up on their latest search they actually thought it was a different property because the picture were so much better. Shots from the realtors iPhone just doesn't cut it anymore... You want it sold, you hire someone to take the photos.