The press release is considered "definitive" for some reason. This is how our PR team explained it to me.
This is actually a very interesting conversation. It is interesting to see that the post on the AWS blog, hosted on TypePad, is seen as more official than the press release.
This may be related to Reg FD. AFAIK press releases are considered fair to investors since they're guaranteed to hit everybody's Bloomberg terminal. Although Jonathan Schwartz convinced the SEC that blogging is compliant with Reg FD, I suspect many companies don't want to risk it.
Yes, Reg FD -- professional IR services cater to this market. In case you're interested in the timeline from the Bloomberg Terminal point of view: http://imgur.com/wwzUp
tl;dr PR newswire (BUS) comes first @ 8:54, it hit Bloomberg News wire four seconds after release. Amazon blog wasn't until 9:17, followed by others such as TechCrunch @ 10:11.
I'm sure that if the press release were being served off a domain that was even a little bit recognizable, like 'thomsonreuters.com' or similar, everybody would be willing to accept that as official. corporate-ir.net just sounds sketchy.
Also i doubt that typepad would be as trusted if your blog wasn't as popular. If it were some company whose blog i've never read before, i wouldn't be inclined to trust announcements from typepad. but everybody here knows the aws blog.
Some public companies (mine included) have specific guidelines around how information is disseminated that can be reasonably be expected to impact share prices. If you look at the NASDAQ website (http://www.nasdaqtrader.com/Trader.aspx?id=MarketWatch) they have their own regulations about how it is handled. I'd imagine there are SEC regulations around it as well.
This is actually a very interesting conversation. It is interesting to see that the post on the AWS blog, hosted on TypePad, is seen as more official than the press release.