Siterubix sites can get traffic. Boy can they get traffic.
Here is an interesting picture for you.
This image might be a bit small so I annotated it. (or you can zoom in)
As you can see, over the last month, my site has steadily improved and has received 6,383 unique visitors. 4,201 of them came from search engines.
Clearly then, siterubix can work very well with SEO. It might take a little while longer than having your own domain, but boy can it work well.
(this site was made in November, and I have been off and on with it for months. I kept abandoning it thinking it wasn't something I could make money from, and I was busy with other sites, but when you are getting this kind of traffic you find it hard to truly quit something)
All I did for this site was follow the WA training. The content wasn't even that great.
Can't show you the actual site now, because I have just upgraded it to my own domain, but as an afterthought I decided to show you the stats. If you are worried your siterubix site is going to fail. It won't fail you if you follow your training.