I'm running SaaS for B2B and it's successful now for 2 years. I started in 2008 and till 2014 was only covering the expenses. I changed my thinking from "If You Build It, They Will Come" to marketing and this really changed acquisition of new users.
In 2013 I also started another SaaS - monitoring service (Piltek - http://www.piltek.com/), but it doesn't have a lot of customers as the only thing I did was developing it an put it online. I didn't do any marketing (only 1 week at the beginning) as I focus on my first SaaS. It takes a lot of time to build and grow a company (if you are alone and bootstrapped).
In 2013 I also started another SaaS - monitoring service (Piltek - http://www.piltek.com/), but it doesn't have a lot of customers as the only thing I did was developing it an put it online. I didn't do any marketing (only 1 week at the beginning) as I focus on my first SaaS. It takes a lot of time to build and grow a company (if you are alone and bootstrapped).