I love reading about how big sites use Amazon EC2. If “this post from Instagram”:http://instagram-engineering.tumblr.com/post/13649370142/what-powers-instagram-hundreds-of-instances-dozens-of is still accurate, they must be at something like $50k/month in hosting costs. Their user base has doubled in the 4 months since they posted that.
My setup for Tweet Marker is trivial by comparison, but to me — without Instagram’s $7 million in funding — it’s a very big deal. What I wrote “back in October”:http://www.manton.org/2011/10/redisonly_migration.html about moving to Redis is still mostly true, although I’ve added MySQL and Sphinx to the mix. I now run with 3 Amazon EC2 “medium” instances and have 5 web dynos (with 3 Unicorn processes each) at Heroku.
I put everything from donations back into the servers. For Tweet Marker to work, it had to be rock solid. It had to scale. It’s only the first week for “Tweet Marker Plus”:http://tweetmarker.net/plus subscriptions, but already I have a good feeling that it’ll all pay off.