Why websites maintain email lists (and perform dark arts)?

We have touched upon the subject of email lists before. Though I regret not maintaining it, I do not do it for the continued reason that:

• I am lazy
• I do not think I have intelligent enough things to say that people want to read every week/fortnight/year

But with my enhanced ability to take BS, I do subscribe to a lot of email lists and have a really good conclusion on why websites (especially internet marketing websites) talk about email lists way more than blogs and forums. First the conclusion: maintaining email lists and pumping them information including product advice, affiliate links, and the likes are like people performing dark arts. Yes, more than a few people fall to the advice to earn some money, and fame to the practitioners. No, there are not a lot of people practicing dark arts for the good of humanity.

I will not harp on the goodness of email lists, that has been done before. But it is equally interesting on how email lists avoid the pitfalls and negatives while you are demonstrating your expertise in a public forum.

• Email lists are private. The reader either opens the email or no, the reader may click on the links or otherwise, and the reader may simply move the damn thing to spam. At the end of the day, this remains private. I am free to claim what I want to claim. I do not have to provide insights into how many returning readers actually come over to the website, what percentage of traffic is from email list subscribers, what percentage of readers are led by my other dark arts, and so on. This is crucial while I am trying to play the expert giving some 'gyan' to the lesser mortals
• Opinions are mostly kept private. Unless someone (like me) erupts in some forum or website, the email responses are private, and kept that way. Strong opinions on emails from the website are neatly sidelined. There is no way to discuss what is there in the list and whether this helps or harms the user. This is a one way water hose, the information from which has to be carefully cross examined elsewhere. Often (as in the case of internet marking software), BS is way way beyond what is reasonable. As a result you may not find any negative opinions for the first five pages of a search engine result. You have to really deep-dive in the topic, visit a lot of internet markets forums and find out by yourself
• You can share silly information and disguise it as a thorough professional quality work. People click on something that is "free for 10 days", "free only for the loyal subscribers of the lists", "free for idiots", look at something that has been rehashed and resold from a totally unrelated story and get satisfied for the day. This especially builds up the opinion provided the subscribers do not know what a feed reader is and do not know what is going on other than what has been provided in online/offline newspapers, Facebook and the great knowledge repository called Twitter. Read here for an example. I totally agree this is needless here (especially while I have singled out the website somewhere else before), but this was just to show the trend.