I have never done this yet myself but I can see how this would help.
TGR, - You asked about the
PR on the press release site.
That shouldn't really matter that much. At the end of the day, a lot of sites publish and email their members press releases explaining whatever it is they are subscribed to.
If you have good knowledge in a particular field that you think may be of interest to others, you would submit your press release to one of these sites and they will publish it (if they like it and think it will be of use) and give you the kudos. i.e. a mention at the bottom of who the author is and a link to your site.
That in itself is worth a lot as people will trust your judgement and also, they may use your information on their site with a link to you.
That in itself is worth something.