Distributed Denial of Service (DDoS) attacks are an increasing threat on the Internet. One of the reasons is that Web sites selling attacks for prices starting from $1.00 are becoming popular. These Web sites, called Booters, facilitate attacks by making transparent the needed infrastructure to perform attacks and by lowering the knowledge to control it. As a consequence, any user on the Internet is able to launch attacks at any time. Although security experts and operators acknowledge the potential of Booters for DDoS attacks, little is known about Booters operational aspects in terms of users, attacks and infrastructure. The existing works that investigate this phenomenon are all restricted to the analysis of a single Booter and therefore provide a narrow overview of the phenomenon. In this paper we extend the existing work by providing an extensive analysis on 15 distinct Booters. We analyze their operational databases containing logs of users, attacks, and the infrastructure used to perform attacks. Among our findings we reveal that (i) some Booters have several database records completely equal, (ii) users that access Booters via proxies and VPNs performed much more attacks than those that accessed using a single IP address, and (iii) the infrastructure used to perform attacks is slightly different from what is known through existing work. The contribution of our work is to bring awareness of Booter characteristics facilitating future works to mitigate this phenomenon.