Surprised to not see Moz on here: while I think they were technically a consultancy at first, their chief export for quite a few years came in the form of incredibly valuable blog posts. My favorite is the 91-point eCommerce conversion checklist:
I sort of put 37signals in that bucket as well even though they did a lot more consulting, their blog was pretty huge in the very small standards web community of the early Zeldman era.
Amy Hoy has spoken a lot about this. I think we're about to see a wave of new startups that focus first on info-products that involve blogs at some stage, then later pivoting into a SaaS product.
This is exactly what I'm doing right now. Everything works as one big marketing funnel from tweets/pins/posts to free downloadable content and one-off landing pages, to single page apps, to e-books and videos, all the way up to SaaS. I have to come to love the term Amy uses for these: e-bombs. Finding customer pains and dropping e-bombs on them is a really lean way to learn a ton quickly, build an audience, and even make money.
If you get really good, you can make it into a repeatable process that works over and over regardless of your domain experience. That said, I still think it might be a little difficult for me to do this for, say, theoretical physicists. I'm personally inclined to partner up with domain experts rather than trying to do it all myself as a lone technologist.
Great examples in the post. Now let's see some more! I've seen Moz and 37signals mentioned. Who else are we missing?
Seems like most of the comments on here aren't getting it. The article isn't talking about products that were discussed on a blog; it's referring to blogs that pivoted into a product.
Deezer was originally a blog called Blogmusik. It was streaming music illegally and was shut down following a trial by the French equivalent of RIAA, then re-launched as Deezer.
EDIT: I realized that Deezer is not well-known in the US. It is a major music startup competing with the likes of Spotify and rdio in the rest of the world.
Ideally we want to say "Businesses that started as blogs". SEOBook is a great example, Aaron started it as a blog in 2005 where he used to put daily seo news, then he slowly converted it into a business and is now offering tools and there is a paid forum. SEOMoz is another such example.
There are several examples of startups taking a blog-first approach. While I was writing this, I found it surprising no one else was talking about this.
http://moz.com/blog/holygrail-of-ecommerce-conversion-optimi...