The Yahoo API
key is very useful because it allows you to make 5000 requests per day to
the Yahoo search engine. However, if you have more than one project, or if
your project has more than 5000 keywords, one key is just not
enough.

Advanced Link Manager allows you to enter more than one Yahoo API
key and when the 5000 limit of the first key is reached, the next key is
used automatically.
