Responses to the above article and other critiques of "ee.g." (insisting on "e.g.") roundly dismiss it as an aberration and even vilify it. Yet it's not by accident that multiple people have raised this question over the years. It's surely not a typo, and it almost certainly refers back to the same scriptorial Latin doubling technique that has given us "pp." for paginae ("pp." doesn't mean "page page" any more than "ee." means "example example," to answer a previous commenter; same goes for "et sqq." as plural of "et seq." and "LL.D." meaning "legum doctor" or doctor of laws plural).
Therefore, "ee.g." may be taken to mean "exemplōrum gratiā" (for the sake of examples) as some have suggested, and be used as a plural. (Probably not "exemplōrum gratiāe" adjectivalizing, as "ee.g." likely means "for the sake of examples" and not "welcome examples." This line of reasoning, however, could invalidate "ee.g." as well, since "for the sake of example" could be argued to obviate the need for number. New Latin and New Greek are like that.)
Now, I have seen "ee.gg." in some texts, which may not be justifiable with the same argument; it is likely that earlier writers mistook the "g" not as an adverb but as a plural, which as I mentioned above doesn't make sense.
So, Mommy and Daddy, may I use "ee.g." or will I get spankedd and sentt to bedd without suppper?