I think the author makes some reasonable points. Although I'm rolling out the 'no true Scotsman' fallacy here, real marketers are invaluable in the same way that real designers are. But you need to understand their true function in order to make best use of them. Marketers also face problems that are similar to those designers face; unsurprising given they employ similar methods that produce outputs that are difficult to quantify.

I'm sure the designers here have all had the following experience at some point:

- designer: I'm a designer at x company.

- other person: Oh, so you make pretty pictures in Photoshop?

- designer: Urghh......

There are similar public misunderstandings about what good marketing is, and what it does. Because of this, they get brought in at the wrong stage of the process, where there's little scope for them to add value. Take talented designers, for example. Ideally, they're part of the product development team from day 1, working side-by-side with devs.

In addition to product improvements that occur when you use 'good design' practices, a good designer will take early concepts and product prototypes, at various stages of development, define appropriate metrics to measure 'goodness', and then test these pre-release bits of work on a representative sample of your target market.

And I don't mean just focus group studies, I'm including other methods too. For example, 1 on 1 'intense observation' type studies, to see how people interact with your product, what they find confusing, unintuitive, annoying etc. Observation, not asking (people lie, people post-rationalise etc.) These insights are then brought back to the product development team and addressed in future development cycles, resulting in a better final product.

If you don't understand this, you will bring designers in after the product is done and you want someone to make a 'nice website' for launch.

Past-Apple and current-Apple are great case-studies here. Past-Apple was a fanatically design-led company who understood design in the more useful sense of the word: it's not about making things pretty, it's about making your product meet the needs and preferences of your target market (one of which might be 'prettiness'). Jobs, I believe, was designer at heart. Current-Apple seems to have forgotten all this, and reverted to the more typical 'good design is pretty things' approach. I won't get in to the results, as I think HN is already well acquainted (going off the recent hand-wringing over the new Macbook Pro).

Although some developers can successfully moonlight as designers, by-and-large developers are terrible designers. Not only do they fall in to the same trap that everyone else does (designing the product for themselves, instead of the people they intend to sell the product to), but because they are highly-skilled technical people, what may seem completely intuitive to them is almost always unintuitive to the non-technical general public, thus compounding the first problem. And you end up with a brilliant technical piece of work that is unusable and unsellable

So, on marketing. Just as people mistake design for 'making things pretty', I believe they also mistake marketing as 'spreading the word after the product is bedded down'. If anything, the skills of good marketers are best employed before product development begins. A lot of this work will revolve around market data acquisition and quantitative analysis. In a sense, they're like 'strategic designers': instead of telling you your target market will find your product hard to use (and here's how to fix it), they'll tell you which market is the richest target (giving you a starting point for your product design), or that you shouldn't be developing your product at all (as there's no market for it).

Good marketing is not solely (nor primarily) concerned with persuading as many people as possible to buy your product, given a fixed product and pre-selected market. I mean, yes marketers (even mediocre ones) can polish a turd, but at the end of the day it's still just a shiny turd. It's trite, but good products are easier to market than bad ones are. Stealing from 'The West Wing': "Bad marketing wasn't the reason people didn't buy new coke; they didn't buy it because they didn't like new coke". It was a product, which I'm sure had lots of clever technical work put in to it, that had no market to sell in to.

I suppose the challenge is dealing with the high signal-to-noise ratio. There are many more shitty marketers out there than there are good ones. The shitty ones don't actually do marketing (they're salesmen, who do sales). I think a key part of this is understanding what marketing is, and how it can be used to maximum effect.

tl;dr: When people understand the true function of 'design', it can be used to great effect. The same applies to marketing, which is a remarkably similar discipline.