Pretty much every post on http://weddinglovely.com/blog/ is by one of our vendors, uses our vendor's content, or promotes a vendor. :)
Blog just has been blogging at least 1x daily, getting the vendors who we promote to promote the posts about them, and making sure the SEO is semi-right (there is a big SEO issue I've yet to fix, but it's not disastrous).
Vendors almost always signup under a free account, and through these promotion opportunities, we eventually encourage about 10% to upgrade.
Blog just has been blogging at least 1x daily, getting the vendors who we promote to promote the posts about them, and making sure the SEO is semi-right (there is a big SEO issue I've yet to fix, but it's not disastrous).
Vendors almost always signup under a free account, and through these promotion opportunities, we eventually encourage about 10% to upgrade.
Hope that helps!