Duncan Riley notes some suggestions on link etiquette for blogs:
Primary source:
If the primary source for the post comes from another blog (an exclusive) a link is desirable in the first line. For example: zyz reports [link], or xyz fact according to a report at [link].
The negation to this rule: if you’ve been approached by the source directly (media release, tip, exclusive etc) or if multiple sites are reporting the facts having obtained the data the same way.
Via source:
It’s good form to include a via link in a post if you’ve obtained the story idea via another site or blog. Format: (via: [link]). This is one part of attribution that seems to be dying out. It’s unfortunate, because it was one of the features that helped build the blogosphere.
Quote/ Inline source:
Where the source isn’t primary (they are reporting it second hand, most commonly with MSM), you can quote the external site within the post as an alternative to a via link. This has become more common than a via link, but it’s really only desirable if you can make it work within the context of the post. I’ve always used with direct quoting: Format: [link] says/ reports “xyz.”
Photo credits:
These weren’t really discussed in the old days, but in an age of litigious copyright holders it’s always safer to give a photo credit when using non-default imagery (in particular photos). Format: photocredit: [link]. The other alternative is to use blog safe photos and I tend to use Wikimedia Commons.
The Honesty Catch:
There are times when blogs write about stories where other blogs have recently written about the same thing, without the second site knowing the first site wrote about it. I’ve had this happen a couple of times in the last 12 months, with people demanding attribution when I’ve sourced the idea usually from a direct email from the company/ startup or site. I don’t believe a link is due where the author honestly wasn’t aware of the earlier article, and lets face it, if you really looked hard enough you’d nearly always find something has been written about before.
Its a nicely done code, I think we'll try to follow something like this as a standard in future.
By the way, there have also been times when our stuff has been taken sans attribution, and even packaged as "research" by 3rd parties to sell to their clients. In fact the reason for Duncan's post is that there is a little bit of whinging going on in the Bitch-o-sphere about Ars Technica apparently holding back for 2-3 days before putting a good overview article in and not linking back to the (supposed) originators. Hmmm sez I, on 3 counts:
(i) Actually, I like overview articles written with a sense of perspective - its that editing value add
(ii) Ars Tech are hardly alone here - nearly all the MSM do it, and are often lauded (erm - sucked up to?) by bloggers
(iii) A-listers whinging about others taking their material and not attributing it is a bit rich, more than one "A List" blog has done this sort of thing.