Without the internet, these blogs would not exist. If the blogs didnt exist, neither would the deals. Let the bloggers have at it. They normally are a day late and a dollar short.
There is a similar discussion on Mystery Shopping on a website I frequent. Every once in a while there will be a blogger or TV show that attempts to profit off of giving "insider information". It is pretty much old information that anyone with any knowledge of the industry at all will disregard, or have long been aware of and have moved beyond.
If the people who listen or read about it are lazy, they will give up quickly. If they are knowledgeable and persistent, they will find deals, to post here, that may help all of us long before the bloggers find it.
In the mean time, there will always be deals to be had.