Yahoo API keys are crucial if you're running many SEO tools or applications.
Securing a Yahoo API key is a somewhat convoluted process (see form below), so below we'll walk you through the various steps:
Yahoo API Key Application Screenshot:
1. goto: http://api.search.yahoo.com/webservices/register_application
2. In the 1st field ("Yahoo API"), if you have a Yahoo account already, enter your account name, otherwise create a new account.
3. Where asked to select a radio button for "Authentication method", select "Generic, No user authentication required" and proceed futher - you'll manage to get your API key.
4. After this, fill out the required fields and click to continue.
a. Developer/Company Name - any name will do
b. Product Name - whatever the name of the application or plugin is that you wish to use
c. Contact email - ideally your email address, but I've entered gmail addresses too.
d. Description of Application - again, a simple 2 word description will suffice (eg. WordPress plugin)
e. Required Access Scopes - leave blank
5. Then click the "Continue" button!
6. On the resulting screen, you will be given your Yahoo application ID, which is your Yahoo API key. Copy and paste this code into your application, and you're in business!