Publishing may be a tough business all around these days, but thanks to the internet, there are more publishers than ever.

Many of them won’t survive, of course. And the ones that die won’t just be traditional publishers that fail to adapt to the internet; there are plenty of digital publishers making potentially fatal mistakes too.

When it comes to mistakes publishers make, here are five of the biggest being made today by publishers of all shapes and sizes.

Thinking channel, not multichannel.

If you’ve been distributing your content via dead trees for the past several decades, it’s probably difficult to think of yourself as anything but a ‘print publisher.‘ Likewise, if you’ve been distributing your content via the internet, it’s may be equally challenging to think of yourself as anything but a ‘digital publisher.

Even so, to thrive in the 21st century, most publishers will need to become channel agnostic. There are a growing number of channels through which content can be distributed and monetized.

None is perfect, but each has unique characterstics that can create opportunities if recognized and taken advantage of.

Unfortunately, many publishers are not channel agnostic. Even when they think of themselves as being ‘multichannel‘, their strategy consists of little more than trying to distribute their content in new channels in as close a fashion as possible to the way they distribute that content in the channel(s) they are most comfortable with.

That is not multichannel.

Focusing on sources of traffic, not quality of traffic.

From Twitter to Facebook, there is no doubt that social media has made a huge impact on the way content is distributed and discovered. But for publishers in the business of monetizing content, where your audience comes from is only part of the equation.

Not all audiences are created equal, and investing resources in initiatives that frequently target sites that deliver traffic that doesn’t doesn’t convert or stick around can be a huge mistake.

Thinking revenue sharing is a viable substitute for investment.

Times are tough for many publishers, particularly traditional publishers. That often disincentivizes the kind of investments that are needed long-term in favor of revenue sharing relationships that don’t make sense long-term.

Take, for instance, the high-profile publishers partnering with OnSwipe to create native app-like experiences on the web for their iPad users. OnSwipe offers its ‘technology‘ free of charge in exchange for a share of advertising revenue.

Notwithstanding the the iPad is designed for web browsing, publishers who truly believe that iPad-specific websites are a necessity would be far better off building these themselves.

Maximizing ad impressions instead of optimizing yield.

When it comes to advertising, jacking up the number of ad impressions you serve usually has a negative impact on effective CPM. Unfortunately, many publishers do this, forgetting, of course, that yield is really what counts.

Thinking a pay wall is a paid content strategy.

Reality has sunk in for a growing number of publishers: ad revenue isn’t enough online. Instead of being the business model, it should be a part of a business model. Enter Pay Wall stage left.

There’s just one problem: many of the publishers erecting pay walls believe that a pay wall is a paid content strategy when it isn’t. Pay walls are only an access control mechanism, and as the New York Times demonstrates, an imperfect one at that.

Without a coherent strategy that looks at audience, pricing, etc., a pay wall in and of itself can do little to build a solid revenue stream from paid content.