We just checked and even at retailer Infibeam, Lumia 920 with wireless charger offer is the 2nd best selling phone giving recently launched SGS 4 company.
Nokia has recently started offering Free wireless charger “DT-900 Wireless Charging Plate” with purchase of Lumia 920. While initially it was limited to “Nokia Shop” but now more and more retailers are offering the combo. You can now book Lumia 920 with wireless charging plate offer from Flipkart, Saholic and Snapdeal and may be others as well. Not only this, it is available in Nokia stores and even 3rd party retailer stores like “Sangeetha” with this offer now.
At Saholic, where Lumia 520 is still available, both Lumia 520 and Lumia 920 are present in “Best sellers“. Seems the offer on Lumia 920 is helping it in getting more traction.