Posted By: 
davidcyclebackIt has the photographer's dry stamp (embossed), which might suggest it was sold.  Most real photo postcards don't have the photographer's/studio's name.  If it was sold commercially, the photographer would want his name on it.  
At the least, it would appear that the postcard is by a professional photographer and not a home made job.
Also, I also wonder if the stamp and "Bill" letter are from the same man.