In addition it has been extremely helpful in "attracting" unknown relatives, those individuals, who via a Google or other search had found my site and reached out to me with the suspicion that we indeed were related. This has been the best benefit of the site, in my opinion.
Another reason, is that those who find the site may not be related, but can create a connection that might result in additional information that is not necessarily a new "named" ancestor or relative.
Let me share a recent example:
About a year ago, at my Family History website, I had posted a story of "Four Generations of Bicycle Shops", which recalls the history of Carl Hart Bicycles. In the story I had written that Carl Braunhart, my first cousin three times removed, had started a bicycle shop in Schubin,Germany (now Szubin, Poland) around 1913. The history of that shop includes Carl's move of the shop to Berlin, and after he immigrated to New York City, he started the shop in Brooklyn. He changed his last name to Hart and the shop was passed down to his son and later his grandson. The shop now resides in Middle Island, New York, having been sold to a non-family member.
Included in the post were photos of the Schubin shop, as well as the Berlin, Brooklyn and the current Middle Island shop. Above is the photo of the original shop.
In addition, he contacted the local Szubin Historical Society and library, and I am working with them to see if there is any historical data that may still exist regarding Schubin in the late 1800's up to the 1920's. That may be doubtful because of the war but its worth a try.
So simply posting seemingly innocuous photos may prove very fruitful to your search!