Trust Google to be able to pull something like this off.
So far the Google Photo's app is extremely impressive. Particularly the ability to search photos by their content. As someone who only takes photos on my iPhone my photo library is quite large. If I want to find a specific photo but can't remember where exactly and when I took it then the search function in the Photos.app falls short. Being able to search terms like "Cat" and have all you photos of your kitten presented to you is a powerful feature. Add to that the ability to geo-locate photos by recognising landmarks and you have a compelling reason to use the service.
Skip to five minutes in for the overview of the new Photos app.
It also helps that Google are offering unlimited storage for photos and videos (provided you don't choose to upload in original quality, which is not an issue for photos uploaded from your phone.).
All this seems a little too good to be true right? Google is in the business of selling user data to advertisers after all. Personally I have chose to ignore this. Google Maps, Gmail, Google Docs; these are all great services. Services which surpass the offerings by Google's competitors. I use Google services all day every day. If it means I need to look at targeted ads on websites then so be it. Until Apple and others gets their act together I have no compelling reason to stop using Google's products.