expanding product margins

[m@lyshka]

Пожалуйста, помогите перевести.
expanding product margins
Выражение встречается в следующем контексте:
Only within the past few years amid a return to high prices and expanding product margins (gasoline crack spread—the profit margin that oil refiners receive for "cracking" crude oil into gasoline) pushed to record highs during the first half of 2006 have the rig counts started to show signs of life.
Заранее спасибо

[foxtrot]

увеличение рентабельности реализации продукции, имхо

[m@lyshka]

Спасибо