SMT's are one way to do atomic swaps between crypto's which will allow websites to get away from the outdated model of placing AD's but allow for direct compensation. Now because of my AD blocker, most of the popular sites will ban me unless I allow their sponsored garbage. SMT's make this entire paradigm obsolete by shifting the compensation onto the same basis as Steem.

You can think of the Steem blockchain as an operating system and SMT's as the API that developers use to develop apps for that OS. For example I use the FMX API for cross platform development and the Windows API to develop VCL based (windows only) applications.