How accurate is GeoIP and $_SERVER['REMOTE_ADDR']?

Question

I make a website for my girlfriend and she recently wants to know who is accessing her site. So I use the database of MindMax and I got the list and count of access by country.

However, after monitoring it for a few days, it is comes to our surprise that there are accesses from some countries which the website is not target to. Of course, it does not means that I think it is impossible for people from those countries will be interested but it just rises a question of accuracy. So How accurate is GeoIP and $_SERVER['REMOTE_ADDR'] (which is used to look up)?

I don't care much about those who intentionally hide or fake their IP. I just more interested to know if there is thing out there that may unintentionally make this inaccurate (e.g., routing).

Thanks in advacne.

Answer 1

Well based on their web page their DB is "99.8% accurate on a country level" ...

Answer 2

There was quite a while (months) after I got Wimax service at home when GeoIP didn't have a clue where I was. I presume this is because the IP block that my ISP uses is "new" and hadn't been mapped to anything yet.

I noticed this because a website (that was trying to be "cute" by telling me where I was) said something like "Hello visitor from ... actually, we don't have a clue where you're from." (I imagine that there was a comment about that print statement that said something like /* This should never happen */. )