Jeff Jarvis of BuzzMachine argues for The success of the network:

I have been arguing for as long as anyone would listen that the future of media is less about products and more about networks. It's so nice to be proven right.

Recently, Samir Arora, CEO of Glam, visited to talk about his success story as a network and a platform.

After only a year and a half, Glam has overtaken [iVillage] as the new No. 1 [women's site in the U.S.]. ... iVillage is built in the Yahoo model of sites it owns or controls....

Glam ... is a network. [The above diagram shows] clusters made up of smaller circles, representing their content areas: fashion, beauty, fashion, lifestyle, celebrity, teen. Inside each of those clusters, if you squint, you'll see a small yellow circle. Those are Glam's O&O (owned and operated) sites. All the many purple circles around those in each cluster represent outside, independent blogs and sites in Glam's network. That is the secret to Glam's quick growth without the cost and risk of doing everything itself.

Read the whole thing for details: 400 publishers, 600 sites, some six figure incomes, $15-35 CPM for O&O, $8-15 for the network, O&O represent 30-40% of Glam's revenue for 20-30% of their impressions.

Mike Arrington of TechCrunch is a skeptic:

But Glam isn't really the largest women's site on the Internet - not by a long stretch. Rather, it's a collection of a few sites that they own that generate some page views, plus a big ad sales team that sells ads for 600 or so other blogs and websites.
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Not only will competition hurt Glam, but their network partners will leave them once they grow to a certain size. As soon as it costs less to simply hire a salesperson instead of paying Glam 40% of revenue, they'll leave.

There's some truth to that, but I think it misses some key problems. As each site grows, it's difficult for the owner to match revenue opportunities with sales staff: first too little work for one rep, then too much, then too little for two, etc. Worse, it's a much harder sell: one site with modest traffic vs. a large network with as much traffic as the advertiser wants to buy.

In the comments, satisfied members of the Glam network raise another good point:

fashiontribes.com:

having Glam take care of [selling ads]- & also to group me with other premium fashion & lifestyle blogs - has enabled me to focus on creating content & actually blogging, instead of worrying constantly about making money from my blog. (They keep me from having to deal with actual salespeople, which is also a huge plus.)

I'll give Jarvis the last word:

Google grew by building a network. So did Glam. I say that is a model for survival and growth among media companies. Local newspapers, for example, should be building hyperlocal networks of local blogs; with them, they can expand coverage and reach in ways that were never possible when they depended only on staff.
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I think what separates Glam from, say, Federated Media is that it is a content network and an ad network. Federated made stabs at that but didn't have the means or moxy to create a content brand as Glam did. Glam contributes mightily to the network with its brand, promotion, traffic, and curation. It benefits greatly from a network of content it doesn't have to employ. And the network benefits greatly from getting sales it couldn't otherwise have.