A blind site is one that a network does not have permission to name, mostly because the site has made a decision that its rate card and/or brand equity would be compromised by its disclosure as part of a network. In this instance, the quality of the site may be quite high, as most of its inventory is likely sold directly, by an internal sales team. The site accepts that it will receive a lower rate from the network by not being disclosed, but has made the strategic decision to sell its available inventory at a lower rate rather than not selling it all.

Caveat emptor! The only other reason an individual site would not be disclosed as part of a network is due to poor quality inventory maintained by the network. Quality of content is subjective, but even if a site contains user-generated content or other content that would be objectionable to some, it should be categorized as such by a network in ways that allow advertisers to make their own decision as to whether they care to run within that inventory.

Key take-away: 

• In cases where a reputable network cannot disclose the name of a site, it is typically because the site has its own sales force and sells a majority of their inventory directly to similar advertisers. 
• Advertisers should select a network partner with a spotless reputation when sites cannot be named to ensure that these sites will still meet a strict quality standard.

Conclusion
In this day and age of online advertising, and understanding what it takes to earn the trust and budget of an advertiser, it is surprising that some networks continue to push the envelope on unapproved or inappropriate content. Advertisers should choose their network partners cautiously and ensure they have a strong track record of operating with integrity.

Underscoring the entire transparency debate is the issue of credibility, trust and selecting an ad network partner you know will always make the right decision for your brand, even in your absence. A credible partner will give you as much transparency as you require, whether that means their entire site list or a custom media plan of named sites.