Thanks for asking the question - I say that because I've stated on numerous occasions that the better approach is to add to an existing thread versus creating new threads each and every time. Of course when I make the suggestion a bunch of nutballs come out and say "Who the hell am I to suggest this", say I'm impinging on people's freedom to choose how to post and when to create new threads, etc. Some seriously demented people that take things way too seriously and prefer disorganization.
The SP Iris has posted on here so I'll just use her for an example. If you search for Iris you will get many pages of answers. Some will be review threads, some will be recommendations for X and Iris fits the bill so she'll be named, and the rest are threads where either the name Iris appeared in a different context or Iris herself perhaps wrote something. Could take you anywhere from 2 min to maybe 10 min to filter through everything to get the info. OTOH, if people simply added reviews to an existing thread, that would result in less searching for multiple review threads, you can see the trend/dates to know when people saw her, people could maintain certain info like stats and not repeat them, etc. It's definitely the better way to go.