Lindsay Beyerstein says that Dueholm "starts off with a pretty good summary of Savage's recurring themes: Disclosure, autonomy, reciprocity, and a minimum standard of sexual performance" - but misconstrues Dan's view of monogamy:

Savage's main point is not that monogamy is bad, or even unattainable. He just knows that it's hard work for most people. He wants to debunk the myth that if you're a normal person, and you really love your partner, you will never want to have sex with anyone else. Savage wants people to stop torturing themselves because their desires don't line up with an arbitrary social ideal.

As he sees it, there are two ways of dealing with this predicament.

You can either embrace monogamy as a difficult but worthwhile project because you like to live that way, or you and your partner(s) can figure out some other arrangement that you like better. The first step is being honest with the people you date and choosing people who want what you want. That's one reason why Savage is always harping on disclosure. It's no longer ethical, or practical, to assume everyone wants the same thing. 

Dueholm sees all this as bleak and transactional compared to traditional sexual mores. He thinks Savage is a perfect ethicist for a consumer age. I think he misinterprets Savage as being an ultra-individualistic hedonist. The "Love" part of "Savage Love" isn't incidental. Savage thinks people should be free to seek sexual fulfillment, but that doesn't conflict with his emphasis on community, respect, affection, and love.

Amanda Marcotte is harder on Dueholm and concludes:

By now, it should be well-understood that red states have higher divorce rates than blue states, and part of the reason is that the “old restraints” are far more prevalent in red states, which means more people are creating marriages where there’s poor communication and a lack of looking at each other as individuals, and subsequently more cheating and casual cruelty occurs.

Dan chimes in to clarify his own relationship as "monogamish" and hopes to popularize the term.