There is no such thing as an ideal length for an article - if you ask me.
The length is a result of how much valuable information you have to share and what kind of article you are writing. Some bloggers I have come across prefer to post only small bits at a time. They make up for it by writing two, three or even more post a day.
Steve Pavlina on the other hand writes articles that take you quite a while to read through. Still he manages to keep his audiences interest and is ultra successful.
www.stevepavlina.com/blog (a recent post: 2561 words)
Paul Piotrowski is to be found somewhere in the middle. His articles are well structured and fun to read.
www.inspiredmoneymaker.com (his last post: 762 words)
I am a regular reader of these two blogs. Check them out. There is a lot of good content waiting to be read.
The articles I write vary in length. I posted a pretty long article about video promotion. I researched a lot for it and had a lot to say.
My last post was rather short. My intention was simply to let my readers know about a nice little tool I found (actually I found this on Lynn's blog). I described it a little to get people interested and provided links to this service. I did not have to go into great detail for this. Thats why I kept it short.
To sum it up: The important thing is to remind youself that you are writing for humans and not for computers. Put yourself in your readers position and read your text as if seeing it for the first time. Like it? Find it interesting or even inspiring? Great, than publish it.
Did you have to get up to grab a second cup of coffee? Well, you might want to do a little editing.
Have a successful day,
Philipp
www.philippknoll.com