Because real people at PRWeb look at the press release... it feels more reassuring, as if there's another stage of quality control.
In part, the PRWeb analytics has enabled me to better quantify public relations results. This is helpful when communicating the value of PR to management, for example, I can definitively report to the CEO that, 'We got X number of impressions.'
The coverage we got was nothing short of incredible. I think getting onto Forbes was my favorite.