Is it worth blogging to get site traffic etc?
These guys think it's worth it: http://blog.statuspage.io/how-a-content-marketing-home-run-jump-started-our-company.
Their company blog got them to 25k fast.
https://www.groovehq.com/blog/100k also benefited from blogging, they grew from 30k to 100k pretty fast after starting their blog and shifted their goal to 500k
Blogging / SEO are legitimate channels for sure. I often hear people say you should market/dev 50/50 of the time... but making SaaS might require more dev time upfront, but once it launches you should market it as much as possible i think.