Q:

How should I capitalise headlines for professional Web writing? (Sentence case vs title case)

I'm often uncertain about how I should capitalise headlines for professional writing on the Web.
The two options I'm talking about are:

Just capitalise the first word and any other words that would need
capitalising in a normal sentence (sentence case).
Capitalise Every Word in the Sentence Apart from Articles, Prepositions and Other Bits     and Pieces. (Title Case / Headline Case).

My concerns are:

Sentence case seems easier on the eye to me, and is less aggressive.
Sentence case may seem too casual though, even for the Web, and
appear unprofessional.
Title case can seem 'spammy' and may be associated with low-quality
content.

I'm aware that the Web offers a lot of variety in formality and what is appropriate, so my question focuses specifically on 'Web only' writing that doesn't easily fit into traditional categories such as magazine, newspaper or encyclopaedia content.
TL;DR Should I use title case or sentence case for professional writing on the Web?

A:

I work with an organization that has an official manual of style regarding the web. They strictly enforce sentence case, even in buttons on a web application "Save thing" instead of the more normal "Save Thing."
It comes down to style and standards. It's more important, in my opinion, to be consistent.
For myself, I tend to slow down and read all of the capitalized words in the second example. I speed read a lot of things, and so the Sentence Case doesn't optimize the sentence for my speed consumption. Non-capitalized words I can pretty much ignore. It's not scientific, but it's one opinion.
I think for a headline, you want people to stop and notice, in which case I want Title Case. You mention it's more aggressive, but if it's a headline, you want to be aggressive. You usually want to yell "Hey! Over here!" After the user has committed to reading it, then it's best to switch (as you suggest). The user is now committed, so slow everything down.

A:

I would look around and see how other web sites in my field do it. If I wrote a political blog, I'd look at the most popular politicial blogs.
Difference (from other web sites) is good when it comes to visuals (photography, fashion, design websites etc.), but similarity is better when you provide verbal content (text blogs, news sites etc.). It's all about how easily your site visitors can navigate your site and read your content, so it is good to adhere to what readers are used to.
Other great examples are popular design or typography blogs. They are usually made by people who have training in creating pleasing and at the same time usable web design. I always liked A List Apart, and usually look at some recent web design awards to get inspiration, but always filter this through the related sites mentioned above.

