There seems to be a new photo/image collection social media app every time I look. What are the differences between Tumblr, Flickr, Picasa, We Heart It, Instagram, and similar programs?

I notice some people tend to have more than one of these accounts rather than putting everything in one account, so I assume it’s because there are major differences. How do you know which one (s) are best for you, but also what services to link together (i.e. usually every blog post ends with a link to Pinterest, add to Flickr, add to Tumblr, etc.)?

So, for example, why would I save one to Tumblr vs. to Instagram and so on? And then you add the blog factor — I follow tons of blogs, some use only one picture service, some use more than one. It just seems confusing to me to have different photos on different services when they all could be together. And it’s also become a bit overwhelming managing and keeping track of each account daily and knowing which pictures are where.

Also, on a somewhat related note, what is the best way to organize your favorite sites — shopping, tech, hobbies, etc… and the social links that come with them (i.e. You have the shop official site, then you join the newsletter, then follow the blog, Facebook, Pinterest, Instagram, etc…)? I appreciate any feedback from the community on the different ways everyone keeps track of their info.

Again, forgive any dumb questions. I appreciate any guidance/help.