Randomly rotating experiences in Target

Hello,

I'm looking to to use Adobe Target to run a randomly cycling set of experiences for our website visitors. I.e displaying one of x number of experiences every time they view our webpage, with the experience determined purely by chance. Does anyone know how to:

1) Set up an activity that does this completely randomly (i.e they could see the same experience multiple times), and

2) Set up this activity so that the experience is shown randomly, but does not allow a visitor to see the same experience twice in a row.

I assume there may be a profile script based solution to this, but am unsure of how to approach this myself. Any help would be hugely appreciated!