Also, if it is your own article, don’t excerpt it. :-)
Yes, but if not then I will still excerpt it even if the source is not on the excerpt list. Bandwidth costs money, long articles with hundreds of refreshes adds up to money JimRob doesn’t need to pay for. Use their bandwidth instead to read the whole article.
It’s also nice for presentation. No one wants to wade through 50 paragraph manifesto to get down to the comments. It makes it alot easier of the gist of the article is put in the excerpt and left to the user to go find more or not. Especially if you’re like me and want to get the point of things to decide if I want to investigate further. It saves time that way and I can get alot more read.
I agree though, use the 300 word limit, and put the point of the article in if possible and pertinent details.
Of course, if you have given up the article copyright, then it's only your article in the sense of authorship. In the legal sense, you may then still need to excerpt it for posting on FR.