Recently SGM took the decision to make MT online a "member benefit". For an organization dedicated to promoting microbiology to expend the time and effort producing something as good as Microbiology Today and then to lock it away so that only people who have already signed up can read it would be a stupid (although possibly understandable) decision. The idea that people will engage with a learned society because they will be able to read a magazine online a few weeks before they would otherwise be able to read it is implausible, unsupported by evidence, and possibly laughable.
Why locking this content away would be a stupid decision
SGM, like other learned societies, is not in the content business - it's in the society business. But seduced by decades of income from content publishing, learned societies have started to believe they are publishers rather than being dedicated to promoting their core interest - in this case, microbiology. If you want to understand why being in the content business is a dumb idea, read The Trouble With Content by Jeff Jarvis.
SGM, like other learned societies, is not a publisher, it is a platform. Unless it understands that and acts accordingly, it is doomed via the disintermediation of the Internet. Forget about raising income, unless the platform serves the interest, the future is bleak. Content is a product, it is not the interest that learned societies must serve.
So here's the good news. SGM has decided to make the superb content of Microbiology Today free to all at the time of publication, although only in PDF format. This is a smart move as it will recruit new members. The thing that is missing now is an explicit copyright statement to enable people who read the content know what they are able to do with it. By adopting a Creative Commons licence as forward looking publishers are increasingly doing, SGM gets the best of both worlds, publishing great content while acting like a society and engaging new members.
I am a currently an elected member of the Society for General Microbiology Communications Committee, but the opinions expressed here are my own and do not represent those of the SGM or any other organization.