"What’s up with these dl.dropbox.com High PA & DA links?" You know, It's frustrating to spend almost an entire day getting a few great link backs... then to find out your competitor has hundreds of cheap & easy link backs for the keyword you are going for with greater Authority [according to SEOmoz's OSE]. So I ran a search on one of our top competitors in Open Site Explorer to gather an idea of where the heck they are getting all of their links. Please feel free to copy my actions so you can see what I see. Run a search in OSE for www[dot]webstaurantstore[dot]com. Click on the ‘Anchor Text’ Tab. Click on the first Anchor Text Term, which should be ‘restaurant supplies’ :: Then it will expand, click on the ‘View more links and details in the inbound links section.’ As you scroll down the list you will notice that they have a bunch of linking pages from dl.dropbox.com, all of them are .pdb files, for their targeted Anchor Text, restaurant supplies. Q: So my question is can someone please elaborate on what .pdb files are and how they are getting this to work for them so well? Also you will notice, on the expanded Anchor Text Page, that their 6^th most powerful link for this phrase (restaurant supplies) seems to be linked straight from a porn site, I thought Google does not rank adult sites like this? Q: For future reference, does anyone know legitimate websites to maybe file an SEO manipulation complaint? Thanks!