Attenetion! Bloggers Are Losing Money by Not Doing Sponsored Reviews

What is the medium with the largest advertising spending on earth? Television. How are the ads displayed there? Between the editorial content, using the same format (i.e., video). That is why television ads are so effective for advertisers and so lucrative for television companies, because viewers will inevitably pay attention to the ads.
Can we say the same about content based websites, like blogs? Not exactly. If you consider Google AdSense or banner ads, the most used monetization methods, you’ll conclude that they practically separate from the editorial content. For example, if you have a blog and display ads on your sidebar only your readers will be able to completely ignore the ads if so they desire. Some even use ad-blockers, so they won’t see your AdSense units or banners no matter where you place them.
What would the equivalent of a television ad be for a blog? Probably an advertorial, which is an article written by the advertiser about his product, and posted in the blog like any other post. A close alternative are the sponsored reviews, which are posts written by the blogger reviewing a certain product or service. Most bloggers prefer this model because they get to write the content themselves, and readers won’t be annoyed with a different writing style/author.
And here is a fact that re-enforces the similarity of sponsored reviews/advertorials with television ads: If you ask any advertiser whether he prefers to pay for a banner ad or for a sponsored review, he will certainly say the sponsored review. Why? Because he will get a much better return on investment, as the sponsored review will give his product a better and greater kind of exposure with the readers of that blog.
As a result, sponsored reviews are probably one of the most lucrative ways to monetize a blog. Last week one company offered me $800 to write a review about its latest product. It was related to my niche, and I was sure most of my readers would find it useful. Despite that I turned the offer down, because I don’t do sponsored reviews.
But this made me wonder: are most bloggers leaving money on the table by not doing sponsored reviews? For example, if I started doing them on this blog I could easily add another $3,000 per month in revenues (considering one sponsored review per week), which would basically double my advertising revenue on the blog. I believe this proportion is true for most bloggers. That is, if they started doing sponsored reviews they would double their advertising income.
So why sponsored reviews are not widely used? Probably because there was a lot of controversy when companies started exploring this advertising model. For example, PayPerPost initially didn’t require a disclosure on the reviews, and people started questioning the ethical aspects of the whole thing.
That being said, I think it is possible for a blogger to do sponsored reviews while keeping his integrity. There are 3 main requirements:

1. a clear disclosure on each review,
2. honesty while writing the review,
3. and the choice of products that are truly relevant and useful for the readers.

Other people claimed that sponsored posts could get you in trouble with Google, but this is not true as long as you use the nofollow attribute on the links inside the review. Google doesn’t have a problem with sponsored links, as long as you clearly label them as such.
Personally I am still on the fence regarding sponsored reviews, so no, I am not stating that all bloggers should start doing them. What I wanted is to raise the questions, and see what other people think. Why aren’t you writing sponsored reviews on your blog? Would you be turned off by them on a blog you read? Do you think the model could work if the requirements I mentioned are present?