GigaOm launched a subscription only blogging service this morning at GigaOm Pro. There’s a great overview of the service on the GigaOm blog. The market for blog content is maturing.

As blogs caught on, web pundits began writing their thoughts online. For various reasons, these writers sought a large readership. To that end, bloggers gave away their thoughts for free. Authors correctly understood they were competing for the time of their audience against newspapers and magazines. To compete effectively, bloggers leveraged their greatest advantage: no marginal cost of distribution on the web.

As the audiences for blogs grew, advertising revenue was enough to sustain bloggers costs for bandwidth, hosting and staff.  But the advertising market has contracted, or at least payouts are smaller than they once were. And today, it’s may not be enough to support the industry.

Nevertheless, there will always be value in investigative journalism, intelligent analysis and thoughtful commentary that rises. And so, the revenue model must shift. I expect other blogs with significant audiences, niche or otherwise, to move to this model and sustain much higher margins than their paper-printing, truck delivering predecessors.

Update: looks like Adriana Huffington disagrees with me: “Subscriptions only work selling weird porn”