The right still dominates ... But the left has mounted a fightback thanks to the generous cheque books of the trade unions, which fund sites such as the policy-heavy Left Foot Forward, set up by former Treasury spinner and political heir Will Straw (Jack Straw's son), as well as the irreverent lefty gossip blog Political Scrapbook.
When Ed Miliband was putting together his office after winning the Labour leadership, one of his first appointments was Alex Smith, ex- editor of the union-funded site LabourList, set up in 2008 by the former Labour spin doctor Derek Draper.
We liberals and libertarians write our pieces and, if they are good and people read them, then we might get money from people who willingly advertise with us.
Conversely, those on the Left take fat cheques from vested interests before they even start—and then must ensure that their political paymasters are happy. And, just as in Ed Miliband's case, the political paymasters are all too often the unions.
UPDATE: johnb points out that this is a totally flippant suggestion.
Not sure that's a fair comparison. People on the left like Chris Dillow and I write for the reasons you suggest; meanwhile on the right, the ASI and the TPA are heavily funded by political donors who dictate the direction of content.
Well, yes and no. First, the Standard article does concern itself with the higher-traffic, politically influential end of the blogging spectrum—and the Lefty blogs that said piece mentions fit into that category.
Second, I would class John B as a liberal, rather than a socialist.
Third, the ASI and the TPA are not primarily blogging entities: they are political think-tanks that just happen to run blogs. By comparison, LabourList, Left Foot Forward or Political Scrapbook are primarily blogs—not think-tanks.