Submitting press release has always been helping me gain high page rank on Google. For quite a while now, I have come to realize that press release sites are well indexed by Google search robots more than a host of article directories.
You see, when you publish a release, search spiders automatically picks them in few days and present them to the world. Press personnels can as well pick your release and reprint it on their high trafficked site.
And also, press release sites have a network of other sites where you release gets to appear. It's not limited to the site you submitted it to. this increases your back links and subsequently your ranking on search engine
Thirdly, your release would be published immediately and gets syndicated on major search engines even before your articles are reviewed.
Don't neglect press release distribution because it can help you attract more traffic as well as increase your page rank which is the real thing online.
That's all for now!