Looking at the chart, you can see how people didn't wake up one day and decide to Google the Nokia Lumia 520. Instead, the phone started slowly and started to pick up momentum until it became the most searched Nokia Lumia handset. And the device has become successful and known for more than just being searched for on Google. According to data from mobile ad network AdDuplex, the Nokia Lumia 520 had 4.4% of the global Windows Phone 8 market in less than a month. Some of the models that were overtaken in market share by the Nokia Lumia 520 include the Nokia Lumia 720, Nokia Lumia 822, HTC 8S and the Nokia Lumia 900.
If the increasing number of searches for the Nokia Lumia 520 leads to sales, the entry-level Lumia model might soon find itself as the Finnish manufacturer's top selling phone. Consider how hot the Nokia Lumia 521 variant of the phone has been in the U.S. where it sold out on HSN, Walmart and on T-Mobile's pre-paid service. Nokia is obviously hitting the right buttons with the device.
source: GoogleTrends via WMPoweruser