I've been a Flickr Pro member since 2006. I store all of my photos there (currently 10,078) and they provide the images for my old blog (BusDriverJim) as well as this one. I use a technique called hot-linking where the link to each image goes directly to Flickr's server. This technique is normally frowned upon if you don't own the photo and pay for the service, which I do in both cases.
I have continued to pay Flickr $25 bucks a year for Pro even when the free service started blurring the lines, but I felt it was the right thing to do. Two years ago they doubled the rate but I didn't have to pay $50 bucks until now as they let their Pro members grandfather in.
Flickr was owned by Yahoo! and has now been bought out by SmugMug. They are currently in the process of moving billions of photos and over 100 million accounts over to AWS (Amazon Web Services) which is the biggest and baddest cloud service on the planet. When done, everything should be faster and more secure.
The service will be down on May 22 for about 12 hours while they flip the switch, which means that neither one of my blogs will have photos. No big deal I suppose and I'll be traveling down to Florida with Brian during that time. My only concern is that links to the images might change, at which point my blogs are toast. I can't imagine they would do that, but I'll find out on the 23rd.