What is good "Add to favorites" percentage?

[Skeewe]

I know its different from site to site, but generally speaking what ratio may be considered as good?
Any other thoughts on this matter? How important that number is?

Regards

[Xander]

I think the problem is there is no reliable way of detecting "Add to favorites", and so averages can vary a lot but I would reckon its pretty low X% or even 0.X% percentage for most sites.