Clear Creative Commons licensing tools. Savvy uploaders can set Creative Commons licensing restrictions on any of their shots, both individually and in batches. By default, you can also choose what kind of licensing you want any of your shots to have, which makes it easy if you're a professional photographer to limit what people can do with them. In addition to giving you tools to tweak photo licensing, Flickr also provides fairly simple explanations of each license type, along with links to learn more. Also, photos that have been given more restrictive licensing can't be downloaded, making it easier to keep control of your intellectual property.
Easy uploading tools. Flickr's latest effort to make photos easier to upload to the Web is a big step up from their previous iteration. We took a look at the new version in August and came away impressed. Well, it's still worth using one of the software plug-ins to get right-click mousing access for contextual uploading on any photos from your desktop, the new Web uploader is really great for updating a ton of shots all at once while away from your home machine.
The API. Flickr's API has allowed for a ton of third party applications and services for both personal and communal use of photos. From business cards to coffee mugs, a hosted photo is more useful when you can do more with it than a quick glance.
Geo-tagging. Seeing where pictures have been shot is a neat feature. Even cooler is being able to look at them on a virtual map. Flickr's geo-tagging has gotten even more useful with an overhaul of the built-in map and the addition of Flickr Places, which shows city-specific pages containing photos that are related to a region, or have been geo-tagged by the Flickr community. While the majority of consumer cameras don't have built-in GPS receivers, Flickr is future-proofing itself for when it's a standard feature.
Huge community. There's power in numbers, and the mass of users using Flickr makes it vibrant. While there's no way to easily see how much traffic your photos are getting as a whole, Flickr lets people comment, tag, and leave notes on your shot, adding an extra layer of interactivity to a static image. While other photo sharing sites may have a higher count of hosted photos, Flickr's "interestingness" algorithm highlights the way users are interacting with some of the good ones. Users can also open their shots to tagging by other Flickr members, letting other people do some of the heavy tag lifting for them.
No FTP. One of the most useful aspects of these online photo services is that it doubles as an off-site backup for any shots you choose to share, but no such luxury comes for Flickr Pro members. The $25 subscription-based annual membership lets users upload and organize as many photos as they'd like. While this is great, what's missing is a way to manage photos en masse if you decide to go elsewhere. While the closure of Yahoo photos led to the company offering a way to jettison your shots elsewhere, there's no such service on Flickr that does the same thing to your hard drive. Considering how many upload tools there are (both third and first party), it's lame not to offer FTP access.
Pro members can't hotlink to hosted photos. Another quibble for the folks paying for Pro memberships is the inability to paste a hosted shot on an outside blog or Web site without linking back as a huge linked image. I'll give Flickr credit for making it really easy to pick out the size of the shot, but considering you're essentially paying a premium for hosting, you should be able to host a shot without having to give Flickr any link love. Heck, I'd even be happy with bandwidth cap on hotlinked images (similar to how ImageShack handles it), as long as I can do without that giant blue box around my shots.
Confusing photo management scheme. Nearly everyone is accustomed to organizing photos by album. While Apple's latest move is to steer people towards calling them "events," Flickr instead chooses to call them "sets." Unlike albums, sets aren't automatically created when you upload shots unless you specify that. Instead, Flickr chooses to give each user a photo stream, which is one big hit parade of uploaded photos. To organize photos, users must move them one at a time or in a batch (while uploading) into a new set. To complicate matters, for people who want to put multiple sets together in one place, Flickr rolled out "collections"--which to a beginner might sound more like an album than a set. While there is a powerful and useful tool called Organizr, that will let you sort out this mess, it's a hair too complicated for less tech-savvy people to operate.
Intelligently sharing private content is overly complicated. Photos, both individual and in sets, can be set to private, but anyone who wants to see single shots can't just click a private URL you send them. Instead, they have to register with Flickr and befriend you. You then have to authorize that they're your family or contact before they can see the content. Also, if you come across a private photo link, there's no clear and easy way to request access to it from the content's creator without copying the URL and tracking them down to send an inner-network Flickrmail. The good news is there's a "guest pass" system, but this applies only to entire sets or your entire photo stream--not just single shots--which comes back to my organizational quibble about having to piece together shots into a set with each upload.
Overly simple design. Some people love it, others dislike it. Sometimes things can just be too simple. While slide shows and the new Places pages are visually stunning, the photo streams, user profiles, and group photo pools are a little lackluster. Given the success of Apple's recent overhaul of their photo hosting services on .Mac, we'd like to see a little more personal flair and customization make its way onto Flickr. Even just changing the background color would be nice.
Related: The Real Deal: Online photo sharing