The noun publicity can be countable or uncountable. In more general, commonly used, contexts, the plural form will also be publicity. However, in more specific contexts, the plural form can also be publicities e.g. in reference to various types of publicities or a collection of publicities.

Is the media plural or singular?

The Quick Answer

As "media" is a collective noun, you can treat it as singular or plural depending on the sense of your sentence. If you're unsure, play it safe and treat "media" as a plural. (This is even true for those following US convention, which encourages writers to treat collective nouns as singular.)

Why is media plural?

The oxford dictionaries say: The word media comes from the Latin plural of medium. The traditional view is that it should therefore be treated as a plural noun in all its senses in English and be used with a plural rather than a singular verb: the media have not followed the reports (rather than 'has').