The most of this “FREE” eBooks are not really free. You have at least to drop your email address and mostly some more information about yourself. In the best case you get some usable information from the eBook, which is belonging to the general knowledge. In the most cases you only get a promotion for any other services or the eBook ends where it is coming interesting. There you find a link for continuing reading. If you click the link, you’ll end up at a pay site.
The result will be in any case that you get flooded with spam, because your data get traded together with the topic of the eBook. For this reason the scammer will know already in what you are interested. As more information you need to enter as higher will be the earning for your information.
So don’t forget, nothing is for FREE at the world. You have to pay with your personal data. This data are getting used to spam you and this data are getting sold. For this be AWARE from FREE eBooks. You pay in any way with your personal data for information, which you can get free from the Internet if you know how to use some search engines.
If something is free, then it will be written on a web site or it will be downloadable without any registration.
A few days ago one LinkedIn member even tried to earn money by using ad.fly for a self-compiled list of scammer. The greediness is endless from some people.