The FCC rules protect local affiliate stations within their marketing area from duplicate programming by stations outside this area. So, for example, Moultonboro, Carroll county is in the Portland marketing area. If channel 8 (ABC in Portland) is broadcasting THE SAME program channel 5 (ABC Boston), the rules say the provider must block channel 5. If a different program is being broadcast on both channels then they are not blocked. (Channel 9 is a special case)
Center Harbor (Belknap county), by contrast is in the Boston marketing area, so the reverse is true there. Its fairly simple for a cable company to block and unblock a channel town wide in their head end, whereas its not practical for a dish provider to do the same in each receiver nationwide. So, you will find most cable companies blocking/unblocking programming and dish providers just removing channels outside your marketing area.
I have several friends with Moultonboro addresses with dish that just lost Boston all together. Time Warner is switching Boston on and off. This is all done to 'protect' the local affiliates marketing area commercial revenue. Doesn't this make you want to rush to Maine to buy an advertised car?
