How to achieve sprezzatura in blogging

Brad DeLong offers a quick tutorial:

On the internet, if you are to be successful, you need to recognize that you are not S.I. Hayakawa with control over the megaphone. So:

• You need to name, quote from, and link to your targets--real targets, important targets, not ineffectual and marginalized loons (unless you are just in it for entertainment value)--or else people will point out that you did not do so, and you will appear and will be either ignorant, lazy, mendacious, or off-base.
• You need to get to the point quickly: there is lots to read on the internet, and people who chase pointers through fifteen paragraphs only to come across nothing but a weak-tea denunciation of the Noam-Norm axis will be snarky.
• You need to bring information to the table that your readers lack--at least one of these three: new information you have, information others have not been aware of that you can point to, analyses that have not occurred to your readers.