If you live in a really mountainous region and outside a small city then your reception is probably not good and you can scratch that off the list of course. There are websites that can tell you what stations you should get and approximately how strong the signal is, based on your location. Do yourself a huge favor and check those out first before plunking down any dough for this.
For example, I only get two stations OTA: local fox and an abc channel, but neither one come in crystal clear and the strength is not that strong anyway. Plus my home is in a very wooded area and that doesn't help either. OTA is of very little use to me but should be great for anyone close to a big city. The Dish signal is awesome though and I am just thankful that I get a strong signal with that and that I could get all my HD locals that way, so I'm good.