"In 5 or 10 years I think every online retailer will accept Bitcoin." - Gavin Andresen
https://youtu.be/iQ2TOFIgvisAwesome 15 second quote from Gavin during this New York Public Library discussion on May 19, 2015.
My honest opinion is this yes in next 5 years and onwards Bitcoin will be accepted by most of the online retailers.For better understanding we can watch the adoption of Bitcoin in last 6 months and can predict where it will be in future.