Mystery Skin Gifting Odss affected by Champion points/Champ lvl/Champ playtime??

I've found through mystery skin-gifting to my friends and through self-gifting that I've mostly received skins for champs that i have not played very much at all, if at all, as well as almost exclusively for champs that i have no champion points for at all. I have five champs like this, and each one has received multiple skins, with my shaco and fiddlesticks almost having a full roster of skins regardless of the fact that i virtually never play with them. I have somewhere near 8 other champs that i play constantly and i've only received two skins for that entire list of 8 champs, on different champs (thankfully). I wouldn't even mind receiving only average skins for a variety of my champions, even the ones I don't play, but it is very frustrating when you spend a certain amount of real cash on skins for your champions only to find that the investment is as worthwhile as getting your bike a new paint job if you never use it and commute to work on the freeway. And your car has no paint job. at all.