It looks like Facebook isn't willing to slather ads all over the place, at least for now. Before General Motors pulled out of Facebook, company strategists met Facebook to pitch bigger, higher-impact ad units, according to sources. Rather than run sponsored stories, which look like Facebook posts, or smaller units on the right side of the pages, GM asked if it could take over a page. Facebook said "no." But as a public company now, will it be able to hold that line?