Is it worth doing a blog review for a back link?

In recent months reviewing websites and blogs to get a link has become very popular. I think it is mostly due to John Chow who wanted others to review his blog and link to it with certain specific words in order for him to rank No.1 in the Google search engine for those search terms. Up to now more than 900 bloggers have reviewed him. But is it really worth it? hmm.... I am not very sure. In fact it seems Google has now penalized John Chow for it. But lets examine it a bit further to see how things stand.

First let me take John Chow's case. I think it maybe worth to review someone like John Chow, like I did a week back, especially if you have something special to say and the site you are reviewing is great and useful to your readers. The latter is very important because the readers interest comes first. Also JohnChow.com is a high authority site (PageRank 6 in Google) and I hear a link from a site like that is worth more than 20 from a PageRank 1 or 2 site. In addition he has thousands of readers. When he baclinks to someone he refers a lot of traffic to that link (But that traffic is short lived. If you don't have compelling content in your blog those visitors will not return again.)

But what about smaller sites? Like sites with a Google PageRank of 3 or 4?

For example a blog I read called Blogging with Desi Baba, borrowed a page from John and started a review me for a free link program. But he did a small change and told he will not only give a link but he'll highlight the strong points of your review in his blog. And two weeks later he bought a $400 paid review from John Chow to popularize his blog. (I think it was not worth for him to pay so much but that's beside the point.) So many of those who reviewed John Chow, heard about his program too and opted to join it.

Now Desi Baba has already linked to 20 reviews and and he says more reviews are coming in. But what does he give in return? He has only a PageRank 4 blog and a maybe a few hundred readers. (And mind he gives only one link and that too, to the review post only.) Is it worth even for a novice blogger to dedicate an entire post in a blog for Desi Baba in exchange for a PR 4 link? I think that's unreasonable and not worth it even though he has a great blog worth recommending.