I think the debates are needed by those who need the "face time" and enhanced name recognition - Sarah does not need either.
And I don't think she wants to wade into this current mud-slinging where each Republican hopefull is more focused on ripping into each other than the Zero.
They have pretty-much been taking swipes at each other - Sarah has not dinged them, nor has she been dinged by them.
Yeah its done wonders for Perry! lol