Does The Engagement Justify The Means?

Facebook is experimenting with new business models. Well, to be more specific, Facebook is experimenting with new ad concepts.

"[Facebook] has been testing an interactive product that draws willing consumers into the advertising itself. MTV tried it out to promote its latest video music awards, posting clips of Britney Spears, for example, and allowing viewers to post comments about them. Those comments then appeared in other users' News Feeds, the Facebook function that tells you what your friends are doing and saying."

Facebook's CEO Sheryl Sandberg talks about this new model in terms of "demand generation". But just because I want to see what applications my friends might be using or see what they might be doing in their status update, does that same thing apply to what advertising they choose to participate with?

It's a rather fundamental question that gets to the heart of whether or not paid/bought advertising models will continue to thrive. Invasive media while still appropriate in some cases, in the interactive model don't seem to work with the fundamental dynamics of the medium. And yet for the most part, advertisers continue to work in a paid media mindset that places invasive banners, buttons and other types of bill boards across the Web.

I like the fact that the Facebook experiment seems to be attempting a hybrid model between bought and earned media - the brand/service purchases placement and then looks at creating some value for the customer (clips of Spears) to engage in a somewhat meaningful social way (comments).

But the million dollar customer question will be, does the engagement justify the means (in this case the paid Ad) and the subsequent WOM FF feed?? What do you think?