edit: Read-It-Later was a web service initially. The idea behind it is the same as Instapaper. Instapaper released a mobile app before Read-It-Later (though Read-It-Later was around as early as 2007).
Edit: Read-It-Later appears to have launched Apr 8, 2009.
http://blog.ideashower.com/post/15139665330/read-it-later-ip...
Calling Instapaper a simile of Read-It-Later stikes me as misleading.
This is the same reason why even Microsoft has decided to make Office for iOS and Android. They can't just ignore 700 million users (and soon to be much bigger) just because they'd want people to use Windows instead. Windows is a big cash cow for Microsoft, but so is Office (about as big in revenue), and they can't risk losing the Office market to others, and not getting to decide the future format for docs, and other benefits they now get from being the absolute Office leader.
How so? Instapaper is literally one developer; isn't it better to be a market leader on one platform than to spread yourself across two platforms and dilute both applications?
It sounds like once the right team approached him (one that he trusted the quality and business ethics of, and he knew their work) he cut a deal for an Android version.
To me, that seems like an optimal use of limited resources.
Is that Instapaper nets somewhere in the $1-2M range. I'd hardly call that "limited resources." The ability to staff up and/or outsource work effectively is an important skill for a business. You don't get a do-over just because you want to do all the work yourself.
>>> TL;DR: Final estimate is somewhere between 0.15% to 0.60% of the iOS market, netting it somewhere between $875k to $2.3m for the duration of its existence (not yearly)<<<
Marco's personal inclination was to support only platforms that he himself used—that's why he built a free service into Instapaper for the Kindle platform while ignoring the Android platform. I initially had an iPhone and an iPad, on which I owned the Instapaper client, then upgraded to an Android phone. I promptly switched to another service with support for my platform.
I hope that we don't see a "this confirms all my suspicions about Android" type of post in the coming months. The market is nothing like it was when Instapaper first hit it big on iOS (during a period where some of the biggest yielding apps were "Where's my car" and flashlight type products).