Yes I know the saying about assuming things, but here goes anyway. I would think that Sherri meant each site would have to have enough pages to be optimized for 100 phrases. Ideally this would be 100 pages each optimized for one phrase.
The challenge as I see it then is to find 100 good performing phrases for each client, which can be a daunting task. This is especially true for Google, where with 3.5 billion pages indexed, good performing phrases are hard to come by.
Another problem is working with clients that have a limited number of services. Many of my clients are very focused in what they do. If the client is highly specialized, and a small business this compounds the problem. How do we get them to pay for 100 new pages, can they afford it?
These will definitely be trying times for
SEO as an industry, as well as the clients we are trying to help!