I can't imagine life without RDS. I'm a solo developer responsible for a large web app. Before RDS I hosted MySQL on dedicated hardware from Softlayer. I had a dedicated box for the master, one for the slave, and another for storing backups. The DB was about 100GB which made backing up a total nightmare. Mysqldump was too slow, I ended up having to use xtrabackup from Percona. Anyhow it got to the point were I was spending over 50% of my time maintaining the database instead of doing productive things, like building new features for my app.
Then I switched to RDS. I instantly fell in love with snapshots. I love that you can backup your database while it is hot. Sometimes, before doing a scary migration or query I'll take a snapshot just in case. I love that.
Even more amazing is the ability to scale up/down while the database is live. When I was with Softlayer and I needed to migrate to new machines there was always downtime and I always had to pay for both the new machine and the old machine for a small duration of time. Thus migrating would cost a couple grand in lost revenue and servers expenses, not to mention my Friday and Saturday night.
The ability to snapshot hot MySQL databases is nothing new and certainly not unique to RDS. You most likely could have implemented a similar solution when you were running on dedicated hardware. But as a solo dev who isn't an SA/DBA you shouldn't have to deal with that sort of thing, which I think does make you the target market for RDS.
FYI: On Linux, you can do instant snapshots with LVM. This is pretty useful as it's possible to snapshot an InnoDB database as it's running without losing data.
This doesn't work at scale. The IO performance with LVM is terrible. I lost a lot of money trying to implement this. Percona wrote Xtrabackup as a replacement for LVM.
Then I switched to RDS. I instantly fell in love with snapshots. I love that you can backup your database while it is hot. Sometimes, before doing a scary migration or query I'll take a snapshot just in case. I love that.
Even more amazing is the ability to scale up/down while the database is live. When I was with Softlayer and I needed to migrate to new machines there was always downtime and I always had to pay for both the new machine and the old machine for a small duration of time. Thus migrating would cost a couple grand in lost revenue and servers expenses, not to mention my Friday and Saturday night.