Mapping a New, Mobile Internet By Stephen Baker http://www.businessweek.com/m...

liberalarts21さん

Mapping a New, Mobile Internet
By Stephen Baker
http://www.businessweek.com/magazine/
という英文でよくわからない箇所があるので、教えて下さい。

On a snowy winter evening in New York's SoHo neighborhood, a small team of analysts at a startup called Sense Networks is poring over the movements of nearly 4 million cell-phone users over the course of a year. They have been tracked by global positioning systems, by cell towers that catch their signals, or by local Wi-Fi networks that detect their presence. As far as the Sense analysts can see, these people have no names: They are simply dots moving across the maps on Sense's computers. (The data trove comes from a company New York-based Sense will not name.)

Much can be learned, it turns out, from the patterns of those dots moving across the maps. It's possible to see clusters grow around a popular restaurant or retail store. It's also easy to learn about each dot. Business travelers tend to congregate in certain spots in each city. The newly unemployed often shift from the clocklike routine of work to far more random movements. （And Sense can flesh out these digital stick figures with additional data. By noting where dots appear to sleep, the company can assign an average neighborhood income to each one. It then becomes easier to predict whether those spending time near car lots are in the market for luxury brands or economy models.） 以下略

最後のBy noting 以下の一文の意味がよくわかりません。自動翻訳に打ち込むと、概ね、
「それから、駐車場近くで時間を過ごしている人々が高級ブランド品を求めているのか、
低価格モデルを求めているのか予測することが容易になります。」
というような訳になるらしいのですが、どうしてこのような意味になるのかよくわかりません。

構文どおりの直訳と解説付きで模範訳を頂けると助かります。

それからどうしてThenが文頭ではなく、仮主語Itと動詞becomesの間にあるのでしょうか？

こういう場合、何か特別な訳し方とかあるのでしょうか？

よろしくお願いします。