The importance of link popularity is widely known and many articles, theories and applications have been written on topic. We all know by now that having many web sites pointing to your web site increases your Google link popularity and can score your web site higher page ranking and consequently site will be higher in search engine 'natural results'.
What we don't know however, is that running a PPC (pay per click) campaign with Overture can increase a web site's Google link popularity. I wish I could see raising eyebrows of some of you now. In next few paragraphs I'm going to tell you how this method works and like everything in life its pros and cons.
So, running an Overture campaign (regardless of how successful campaign is) will put your advertisement on thousands of web sites (refer to Overture Impressions). It's pretty simple; there are thousands of 'content' web sites that use Overture ads as their main income stream. Similar to Google ads, web sites are publishing Overture ads and once a user clicks on ads, Overture pays a small amount to 'content' web site (for example see http://www.brazil.com , right click on any link on this web site then properties, you'll see that this links back to overture). Once your ad appears on many web sites it's ready to be indexed by Google. Google, using its famous crawler - GoogleBot, visits many web sites each day and there is a high chance that it will find, index and include page that displays your ad in its natural results.
Sounds a bit farfetched? Let's have a look at this example, open a browser, go to Google and type www.orangejewelry.com/ -site:www.orangejewelry.com/ into Google search box. What you will find is around 200+ links to this web site. These are Google's natural results; however, 90% of links in this results set are 'content' pages that run Overture advertisement campaigns!!! www.orangejewelry.com is a new web site on web that runs PPC campaign with Overture, what they found out is that they get an additional value from campaign in form of 'loose links' in Google, which increases link popularity. Again, it's pretty straightforward; www.orangejewelry.com pays Overture to be visible on internet. Overture pays small 'content' web sites to display www.orangejewelry.com ads. Google crawl these web sites, index them and include them in its natural results.
As I mention above, these links are 'loose', which means these are not real links to your web site. The reason is that Overture ads are changing all time and by time that Google picks up page, index it and put it in its natural results real ad or link to your web site is not there, it's changing dynamically by Overture.