I call these schemes "grey hat", since I see this as a grey and at times murky area in which those who game the system gain an unfair advantage over those who choose to abstain; and the last thing we need as writers is to start thinking of our craft as a competitive sport and not as something wonderful in which we all peacefully and healthily cooperate.
The schemes often operate this way: you join an ebook service web site or adopt a twitter hashtag to get other members or hashtag users to tag your book at Amazon (with labels like "dystopia" or "science fiction") so that it appears in more search categories and is more visible to customers; and in return, you reciprocate by tagging other people's books. It's one thing doing this for a friend where you have a genuine interest in their works, but it's a grey area when it comes to tagging others whose works you don't actually know, just so they'll reciprocate. In some cases, the author will comment on a web site discussion thread suggesting tags which they would prefer others to use, and they tag others -- any others -- who've made earlier comments.
As well as tagging or labelling books, requests are also made asking others to click the "like" button beside the title of their book at Amazon, even if these other people know little about the book or have not bought it. Obviously, there's no harm in asking folk who've actually read the book to click on "like" or to write a short customer review at Amazon, if they have a genuine interest in the work. I find this vaguely reminiscent of chain letters and pyramid schemes.
Speaking more generally, I'm not at all happy about the way in which self-published book marketing is being automated at social networks such as twitter, with the use of specialist tools such as tweet adder. We writers are surely sentient human beings who care about such issues, not automatons?
In my opinion -- for what little that may be worth -- we really need to get away from this kind of grey hat scheme and move forward to set up real writers' cooperatives which are respected by readers; which issue genuine and objectively assessed, free "marks of high quality" (like British Standards Institution kite marks) to individual works by their members; and which provide access to genuine and objectively assessed reviews of their members' works. These bodies may charge an annual subscription, but in order to maintain objectivity and respect, in my opinion such services as book review should not be paid for unless payment can be uncoupled from the review process: the outcome of the review should be made purely and simply on the quality and readability of the book itself and not be influenced by the fact that the reviewer has been paid to carry out the work. Obviously, payment is not an issue in the case of feature articles or advertorials.
Sorry, I hope you don't hate me for speaking my mind. This is just my personal opinion, and other people's views on this subject as equally, if not more, valid. I can see, for instance, how such schemes have come about in a bid to level the playing field for disadvantaged self-published authors. Unlike us, the Dissidents aren't afforded this basic freedom of speech.
Anyhow, the best of luck to you in your own endeavours!
• By Etienne de L'Amour ~ Google+