With the road win, the Rams improved their record to 6-6-1. The win was attributed to a late fourth quarter comeback drive by Rams quarterback Sam Bradford. The drive resulted in a touchdown reception by Brandon Gibson, bringing the score to 13-12. The Rams then scored a 2-point conversion on a quick pass to Danny Amendola, making the score 15-12 Rams. With under 2 minutes left in the game, the Bills attempted a comeback of their own, but came up short in what resulted in the Rams win.

Based on the above article, answer a question. How many points did the Rams win by?
3