On Cooking.Stackexchange, we started a blog around the time the Community bulletin was introduced. We would like to get more readers (and writers) from inside our community. The only way new posts get promoted right now is the Community bulletin, and it has a dismal record, resulting in extremely low visibility of the blog. I suspect that many semi-regular users haven't even noticed that there is a blog.
Problem 1: Community members don't notice when there is a new post
As a new blogs with not enough volunteering authors, we started with a cautious schedule, one post every two weeks. The point was to select a modest goal, but make sure that we stick to it. It is possible that more people will start checking regularly by themselves when we move to a once-a-week schedule on a fixed weekday, but for now, they rely on us pushing information which never reaches them. True, a blog post is automatically announced on the Community bulletin for a day or two, but most users don't visit the site in such short periods, so they don't see the notice while it is up, even if they are aware that it could be there.
For evidence, see this meta question where a user complains of not seeing notifications when he'd like to. Note that this is a user from our first page (for this month) - if he doesn't see it, what about the users from the other 215 pages? Note that our meta sees very light use, it is very uncommon for a "normal" user (not a moderator, CHAOSer or a chat regular) to post something there. This seemed to have been enough of a problem to have driven the user to Meta.
Problem 2: The link doesn't get noticed in the period it spends on the Community bulletin
I remember hearing this complain in chat from time to time. I am personally underwhelmed with the Community bulletin too, and many of the people to whom I have contact via chat or meta have expressed similar sentiments, see for example ElendilTheTall's comment on the previously linked question. And our latest visitor numbers confirm it.
We created a blog post two and a half days ago, and it has been visible on the Community bulletins ever since. In this time period, Word Press counted 89 link referrals. Out of those 89 link referrals, only 14 are from a cooking.stackexchange address, and one of them is myself clicking the blog link without being logged in to WP. In the same time, we have had 7 visits from a Pinterest pin made by somebody with only 53 followers. A pin made by somebody random without much social network clout generated half as much traffic as the only official link available to our own community. Also, on the first day of the post, we had 7 views coming in from Cooking.stackexchange and 12 from Facebook. While I am happy to see that our content is good enough to get at least a bit dissemination by word of mouth, I feel that it is very invisible to its target readers - our own community.
Another piece of evidence: A user who knows the StackExchange network well (and is even a community moderator on another network site) heard in chat that we have a blog. His reaction:
how do i even get to the blog? the main site doesnt have a link to it at the top
Problem 3: I don't believe that visitors from outside StackExchange ever notice it.
I am afraid that I don't have hard evidence for that, it is just a feeling. But the design is made so that it blends in, and the title alone - "community bulletin" suggests that it is a) boring and b) nothing for outsiders. Seasoned Advice gets many thousands of page views per day (I'm not allowed to tell you how many exactly), and an overwhelming part of them is search engine traffic, so it is highly unlikely that it is created by registered users. And yet our blog receives 30 visits per day on "normal" days, 70-80 visits per day on the first two days after publication. Sure, many of the Google visitors won't stay around on the site after they have found their information, but if some of them decide to stay with us, we want them to be able to find our quality content - which encompasses both the Q&A and our blog. And I have a feeling that they have practically no chance of finding the blog.
I won't prescribe the StackExchange team how to do their job. But I feel that some changeis needed. And this change will only save the problems outlined here if it offers a prominent link to the blog (visible to all visitors, not only the frequent users who know where to look for it) which also indicates the name and/or date of the latest post, so that semi-frequent visitors have a chance to judge whether they have read the last post or not. I will support any implementation which will solve the problems above, even if it needs a bit more work (e.g. creating a thumbnail image for each blog post which can be displayed). The Community bulletin is not a good solution.