Q: Should I accept an invitation to publish my journal article as a book?
I received from a certain Lambert Academic Publishing an invitation to publish one of my research articles published in a journal in the form of a printed book. The "acquisition editor" states that they are not a conventional publishing that is why they are soliciting articles from authors. She also maintained that I may avail of the following: free of charge publishing; simplified and fast publishing process; worldwide sales of your work; no commitments; you and only you remain the copyright holder of your work; access to eco-friendly Print-on-Demand technology. Is it a case of predatory agreement? What can you say about it? Should I continuously communicate with the e-mail sender?
Lambert Publishing Company does not seem to be a reputable journal. Many researchers report receiving spam emails from them. From the information I gathered online, it seems that they publish poor quality work which is often not peer reviewed properly and sell them at high prices. They generally publish dissertations by young researchers and the copyright rests with the publisher, which makes it impossible for these researchers to publish their work elsewhere later. Although that might not be a problem in your case since your paper has already been published, I don't think you stand to benefit in any way from republishing the same work in the form of a book. Most importantly, since the publisher is not reputable, you should avoid being associated with them in any way.
You can read the following posts for more information about the publisher:
This content belongs to the Journal submission & peer review Stage