I just did a quick Search Engine Optimization test from MSN Live which I was never interested in as compared to Google search results, SEO for MSN Live seems to be baby simple and uncomplicated, perhaps so is their algo too!
The winning technique for MSN Live seems to be the keywords in URL.
You will rank above older and more linked pages if they don't have the keyword in the URL among other factors.
In Google, the wining SEO trick seems to be both page title and anchor text in inbound links, and number and quality of those links.. more sophisticated.
MSN Live seems to weight the page title and on page keywords as a second in importance factor to page URL.
This means it is not hard if you are building pages from scratch to optimize for both search engines with no conflict just as long as you don't keyword spam the URL, title and page content which could lose you Google.
In conclusion, MSN algo at a quick glance is simple and rough, giving less weight to out of page factors, and full weight to on page factors.
I did this test in 20 minutes using some basic keywords from my site for the purpose of exploring if there is anything new on the MSN front.
Please go ahead and do your own tests and let's compare notes here.
In keeping with the thread title, would be very nice if you could tell us what in your opinion accounts for your success on MSN Live, how does one dominate the serps on MSN live, and factors that are specific to that search engine..