Mall

[Freya Mokusei]

Land is never free.

Random malls aren't profitable.

The end.

[Freya Mokusei]

Land is never free.

Random malls aren't profitable.

The end.

[Rolig Loon]

You may build if ----

1. You own the land and pay monthly tier.  (If you are on a private sim, you also need to obey the sim owner's covenant.)
2. You are on a friend's land and you have his permission to build.
3. You are on land owned by your group and you have the group's permission to build.
4. You are in a public sandbox and want to build something temporary (but not a place to sell things)

Otherwise, you may not build.  If you build in a place where the landowner has forgotten to prevent building, your objects will almost certainly be returned when the landowner finds them.

[Syo Emerald]

You have no clue about SL or how business and economy work in SL according to your previous questions. You should keep your hands off buying land (then that is what building a mall would lead to) as long as you don't get yourself some experiance, skill and knowledge.  You don't seem to have any kind of concept and jump randomly from one thing to another, everytime with one-liners.

By the way: Malls are so outdated...