This will likely come as no surprise to anyone: Yahoo has announced that it will shut down Yahoo Meme on May 25th.
Not familiar with Yahoo Meme? That was probably the main problem: Not enough familiarity and adoption.
“…the closest comparison is Twitter. It’s a micro-blogging service where users post updates that can include photos and/or video. Meme supports reposting and following other users to stay abreast of their updates. Sound familiar?”