Should Web App's Blog be on “brand” domain or more “SEO-Friendly” domain?

I know this question gets answered and asked a lot but this is a bit different. thanks in advance for reading and helping!<p>-my web app is an online resume tool with a custom (read: unknown) brand. We are planning on building a career advice blog to help drive traffic to the App. We are planning on building it on a domain that is different from the "brand" that is a direct match to a VERY often (Like hundreds of millions time a month often)searched phrase on google (although it is long... like 17 chars long)... we would just have a "this blog is sponsored by...'our brand'.." written all over the site.<p>I know google is discounting "exact match" URLs in their new SEO algorithms, but I still think it would help drive users from search engines to our unknown brand.<p>What do you think? Opinions input is very helpful! Try to build it on a new SEO friendly domain or build up our current brand? THANKS!