The three at the bottom were free. The Harley & Suicide Squad issue was probably to help promote the first Suicide Squad movie. And the other too are True Believers reissues from Marvel. Those are usually given out to help promote old, first or important issues of characters to get people to get into characters if a movie, show comic event or something is happening soon and they want people to be aware of said character. It can also be a good way to read classic or Golden Age issues. Though also anniversary years can be good for that as fancy reissues can be printed.