We've just come across an article from Joost about making your reputation management look natural. It's a good point and one that we thought was worth summarising here:
The essential point is that someone doing a search for a company or brand is probably looking for one of two things:
1. the company itself 2. reviews
If they are looking for reviews, and you have aggressively managed the first page of Google results to push all reviews below the results you own, then the second category of searcher is going to continue looking until they find the reviews they are looking for.
The suggestion from Joost is therefore to make sure that your reputation management strategy involves boosting some positive reviews up the results. You want these to be natural, good reviews that people have written about your company. Go looking in the mid-reaches of the rankings for the search you are trying to target (pages 2-5 on Google for example) and water them with some link-love to boost them up among your owned results.
Having positive reviews scattered in around the results you own makes it more likely that people will trust you and go ahead and buy from you.
The warning that goes with this is that you won't generally have any control over the content of these sites, so once you have got them ranking well, you are at the mercy of people who come along after that to submit reviews. For this reason, you may consider that positive articles are a better bet as targets for this strategy than review websites where multiple people submit reviews and averages etc. are reported.