I am trying to get my head around Spanish translations.
There are numerous distinct flavors of the language depending on world location. I really cannot say I see sites with multiple Spanish translations, so, if the purpose is to have your site readable to Spanish readers worldwide, what is the best practice to handle these different dialects?
GeoIP is somewhat dangerous to make decisions on site language. I am often surfing from Kazakhstan, but I wouldn't like it if sites presented me the Kazakh or Russian version of their site if also a Dutch or English version is available. GeoIP only tells something about the location of the visitor, not about the language skills.
Just thinking of the large Spanish speaking population in the US who would probably prefer Spanish websites, but are on an us-en IP, or countries where more than one language is spoken like in Switzerland, Belgium or Canada.
To solve the multi-lingual problem, I use content negotiation on a few of my sites where the webserver delivers the language version based on the preferred language settings in the browser. Furthermore on all multi-langual websites I have one-click links on every single page to that pagecontent in other languages. In the end it is the visitor who decides which language he wants to use, not a machine.