Earlier this month, American literary critic Michael Dirda - who reviews for the Washington Post - wrote a column in the Times Literary Supplement about the woes of the newspaper book reviewer.

"Too well educated for an honest trade, they are nonetheless disdained by 'real' journalists who write about politics and business or cover wars and earthquakes."

Quite apart from their lowly status in the newspaper hierarchy, Dirda goes on to bemoan the trials the reviewer faces, being especially galled when adverts or features on "fresh developments in stiletto heels" elbow finely crafted reviews into a corner. Or when a book jacket does not quote his encomium, or if it does, uses only the newspaper's name and not his.

His decidedly egotistical complaints will chime with reviewers of all the arts, be it theatre or books or music. But as one thoughtful TLS reader said, in response to Dirda's column, he entirely ignores the new and flourishing world of online book reviewing, where the constraints that drive him crazy do not exist. According to Hope Leman from Oregon, thanks to a raft of online platforms, "we are entering a democratized, golden age of book reviewing in which women and people of colour can make their voices heard in a way that has not been the case for much of the period of Dirda's career." Nor, indeed, at any previous time. Few realms have, until lately, been more exclusively dominated by white, middle- and upper-class men.

Ms Leman writes for NetGalley and Medium, which appear to be well-organised and wide-ranging in the books they cover. In the UK, there are many online outlets for reviews, one of the most prominent being Lovereading, although a quick search reveals manifold others, geared to suit all kinds of tastes, from the ubiquitous crime, to sci-fi and children's books.

Despite - maybe because - of these new outlets, there is still a marked degree of snobbery in the world of print reviewing. In part this is an inheritance from the intellectual elitism of the past, and in part it is eminently justifiable. Online reviewing is generally not as closely or rigorously edited as reviews that appear in print. What the reader gets is an unfiltered assessment by a someone whose credentials might be no more than a desire to have their say on a book they've picked up and loved, or loathed.

Few of these citizen critics will have spent years reviewing for a living - and if freelance, a very poor living at that. As a result, an online review can sometimes be nothing more than a gush of personal opinion, untempered by knowledge or insight. (The same, of course, can be said of certain print reviews, too.)

As online readers grow more discerning, however, so do reviewers. Ms Leman pointed out that in becoming a reviewer, she has become a better reader. That goes for all of us. Approaching a book with pen and notepad in hand guards against lazy or careless reading. Knowing you have to frame your thoughts for public view is a sure way of paying closer attention. And by extension, those who regularly read online reviews became adept at telling considered analyses from puffery or pique.

That said, there remains a crucial distinction, to my mind, between the unpaid online review and the print review. Web writers tend to be concerned with recommending books, or steering readers away from those not worth their time. There is little sense of a critical conversation, of putting books into a historical literary perspective or drawing attention to ideas or subjects, styles or techniques that the reader might be keen to read about, but never pursue further than the review page.

Some print reviewers' ideas are so illuminating and so well written that their reviews are better than the books they cover. Michael Dirda clearly falls into that category - he won a Pulitzer Prize for his criticism. I've yet to read a body of online reviews that would deserve such an accolade, but there is little doubt that the day is approaching.