Use it for sell threads like this one, for example. http://www.ecocitycraft.com/forum/threads/pis-enchanted-stuff.105258/ Xenforo deletes multiple spaces in a row thus ruining spacebar-adjusted tables.
Similar things that you can do with google docs, I know you can simply use images and post them in but i like the simplicity of every users can use it, unlike having a graphics program. It reduces the number of images on the site (dunno if that can cause any forum lag for people) Couple of Examples: 1. Creating Leaderboards for events. 2. Creativity with keeping financial gains/income/outcome. 3. More organised multiple item selling shops I think as a whole its a nice creative edge people can gain from organising things and create a different twist on looking at topics.