How to implement Scrum in a company with three similar web-based products

Question

I am somewhat familiar with the concepts and benefits of Scrum. With that in mind, I am trying to improve the failing Scrum product management structure of a company I'm now working for that has three separate B2C products, catering to the same demographic and accessible on the same website. Each product has a product owner and a unique development team (5 - 9 people in each) behind it.

Given that the target audiences are similar (not sure if it should matter) and the 3 web products are similar in nature, what are the potential benefits/risks associated with merging the teams and having just one product owner/scrum master/dev team? Some questions that come to mind are: does it make sense to have 3 product owners and three distinct backlogs if your website has three distinct products? Also, if you only have one product owner, what is the best metric off which to choose who that will be?