To me there is a range of poly people. Some use poly as a "lifestyle" between one monogamous relationship and the next as a way to describe themselves and their dating life in terms of being open about who they are seeing. Some use "lifestyle" as a way to describe their sex life as they have partners but engage in a "swinging" style sex life of sleeping with friends or going to poly sex parties that are less couple-centric and hetro-centric than swingers parties.
People who identify with poly and don't consider it to be a "lifestyle" quite often identify with it as they would their sexuality; such as identifying as gay. That isn't a matter of its good for me right now, I could take it or leave it, I am waiting for "the one," I am at a stage in my life when... Its what they are born with.
Personally I don't mind the term lifestyle as long as these differences are clear to those that use the term. Often they aren't. I get uncomfortable with that, but really I just note it, educate on all the differences between types of poly, tell my story and about who I am (I am poly identified) and move on... Which is what I have done here
Good luck with your site. It sounds like you need to know a bit more about poly. Why not read here, do some tag searches and settle in for a bit.