Standard VS Distributed buying model

[ant1kan]

Hi all,

I've seen @Luke's guide and many other threads and one thing I don't get (LOL, I wish it was one!) is the suggested ad distribution model.
Is there a specific reason for not buying smoothly? I'm testing these days some offers to both Zeropark and PropellerAds and everytime
I choose the standard, for PA or "Buy all available traffic", for ZP, my daily budget (3 to 5X) is burned in like half an hour.

Any advise