What it would do is increase the average number of items of interest that you see on the home page. In the current system if you're not interested in 15 of the

What it would do is increase the average number of items of interest that you see on the home page. In the current system if you're not interested in 15 of the articles - then you only see another sample of 15. I'd guess that most users would not use more to see other stories. This approach would let you see 30 of interest... This would lead to more upvoting on stories that don't make the top 30. I guess this would keep the front page "fresher" by allowing for a greater diversity in where upvotes go. To be honest, not sure what the effect would be overall - fresher doesn't necessarily imply a better SnR - but I don't think it's as simple as re-visiting links or the change in color for a:visited.