Read the thread and it should be relatively obvious: Don't sell out and let companies alter, remove, bury, hide or disguise negative reviews (or do so on the companies behalf).

If you really want to beat the incumbents scrape their sites and rehost the deleted content. (If they DMCA you then publish the DMCA notice and note which company the content was related to and when it was published/removed/DMCA'd so as to preserve a record of removed reviews related to that company)