I think the key part comes when he says:
Blocked hit the App Store in early September 2008. I had a modest amount of downloads at first. And then, right after Christmas, sales jumped. I’m not sure what led to Blocked’s being chosen as a staff favorite, but I know that once I started actively promoting it through advertising, Web forums, YouTube, and Twitter, I saw an increase in activity.
In many ways the hard part comes after you've created something.
Take my book, The Geek Atlas, for example. I started writing it in May 2008 and spent 6 months full-time writing and researching. I stopped working and just worked on the book.
In November 2008, I handed the book to O'Reilly and in June of this year the book was published. It was a lot of work by me (and others) to get the book out. Now, do you think anyone cares how much work it was? Does any of that mean it'll sell?
What matters is promotion. I wrote it, it doesn't mean people will buy it. And the main reason they won't buy it is they've never heard of it. The same applies to the sales of iPhone apps.
There are over 25,000 iPhone apps and a small number of slots on the iTunes main page where you can see top apps or recommendations. This is analogous to Amazon.com. My book's one of many, many books and it sure gets a boost when it's on one of Amazon's top-N lists, but what really matters is promotion.
If you've made the effort to create something, make the effort to promote it.
For example, my book was given lots of airtime by Leo Laporte and Steve Gibson on the Security Now #199 podcast. Last week there was an article in the San Francisco Chronicle about it and the same day there was another article in The Times (of London). All of these articles came about because I went out and promoted the book. You can do the same for an iPhone app.
To get my book mentioned in as many high impact places as possible I made a list of every newspaper, magazine, blog and podcast I'd like to see it in. Then I went and found the relevant editor, blog owner, podcaster, etc. I obtained their email addresses. I wrote individual emails to every single one of them, tailored to their publication. Those that responded got free review copies of the book.
In one case, the San Francisco Chronicle, they asked me to write an article for them about the book.
It was a lot of work to make those things happen, but the only way to make a creative work successful is for people to hear about it.
And it doesn't end there. The promotion continues to make sure that people actually received review copies. To see if they have questions and know how to contact me (I handed out my mobile phone number). And I've recorded videos promoting the book.
At some point I realized that O'Reilly wasn't going to have the time to exploit the geekatlas.com domain name that I'd persuaded them to buy. So, I got it from them (thank you!) and set up my own site there. The site is all part of the promotion process.
Most recently I've been asking people who've read the book if they'd be willing to write reviews on Amazon. That's an important part of getting the book into people's hands since I (and everyone else) reads the reviews. I've been doing this by asking people who mention the book on Twitter if they'd write a review. You can search geek atlas and see exactly what I and others have said. (And, BTW, if you've read it please consider writing an honest review on Amazon)
It's not enough to create, you have to market.
PS I've ignored all the wonderful efforts made by the staff of O'Reilly in promoting my book. I didn't mean to downplay your work... I'm just making a point about the effort it takes to get people to hear about The Geek Atlas.