Hi Liz,
Once you have a standardized list of countries & states, you can run cleanup smart campaigns to fix any leads that do not conform to the standard values.
Suggested steps:
1) Establish a standardized list of countries & states (Greg's ISO link is great)
2) Run smart list reports where Country NOT EQUALS standard values, export and map the variations to what the correct country value should be
3) Run clean up smart campaign fixing current leads who have the incorrect country values using Change Data Value flow step. It would look something like this:
4) Once you clean up the current leads in your database, you can set up a trigger campaign (just copy the batch campaign you used to fix the leads) to catch any newly created leads that come in with incorrect country & state values.
This can get tedious if you keep having to add more and more variations so the best way to ensure this is fixed going forward is to create country & state picklists for all of your forms.
Is there are reason you use free form fields instead of a drop down? You can set this up easily in Marketo forms.
If you use Salesforce, they have a standard country list found here: Standard Countries for Address Picklists. If you go into Setup in Salesforce, you'll also see which countries have recognised states too for added value (United States, Canada, Australia, Brazil, China, India, Ireland, Italy and Mexico). Attached is a spreadsheet (2 tabs) I created from here to do my data normalisation and my dropdown creation, this is made up from the above link and the Salesforce State and Country Picklists section (you may need Admin access to see this or I use my Salesforce Developer version [Developer Info - Salesforce Developers | API Documentation, Developer Forums & More / Signup for free - Salesforce Developers]).
Salesforce -> Setup - > Salesforce State and Country Picklists
.png)