How many categories should you have?

How many categories should you have?

I've got 18 categories, which includes the "catch-all" misc and Weblogs categories, yet others have far more. For example, I've written maybe 4-5 posts on educational institutions and blogging, all very popular, so should they get their own category?

I notice that Chris Abraham's Marketing Conversation seems to have like a hundred, and I like how it's done, but is it an effective use of screen real estate? It obvious works for him, as do my 18 categories for me.

Obviously there is no right or wrong answer, but this is a question I've never pondered before.

Since the collective experience of you, my readers and commenters, obvious dwarfs mine (as it should in a Web 2.0 world), any thoughts, opinions, or advice ???

Comments

[Chris Abraham]

I have to say that I don't endorse my own strategy. I am a shameless SEO slut and so I have a tendency to focus more on using Categories and Tags as a tool for folksonomy as opposed to what Categories are supposed to be, which is user-navigation, UI, and Taxonomy.

Does that make sense... I cannot help but think of SEO and keyword density and internal highly textual/topical text-links all-the-firgging-time.

Mea maxima culpa.

[Ted Demopoulos, Blogging for Business]

Chris,
Makes perfect sense -- the SEO benefits are obvious. Hope you're having fun drinking Ale with CC and give him my best!

[Chris Abraham]

I will do. Thanks!

[Angie Hartford]

I believe your readers will thank you for having 18 vs. 100 categories.

[Ted Demopoulos, Blogging for Business]

Thanks Angie,
I do sometimes wonder if my categories should be more granular, but like most things, the number of categories is a trade off. Plus, it's always easier to add more than remove some!