I don't know why this has a picture of Justin Timberlake on it, but the message is relevant.
-Dogs have to go outside to pee. However if they have an accident they will happily eat it. Cats you don't need to take out to go potty. The dog will happily eat the cat's business too.
-Dogs bark at every squirrel. Cats quietly chatter at birds.
-Dogs will hump grandma's leg. Cats will readily identify what's theirs by brushing up against it. Let's just hope they leave it at that.
-You must mortgage the house just to feed the dog. Cats eat less than you do.
-Even ugly mutts are expensive, but kittens are often free
-Dogs smell bad even after a bath. Healthy cats don't need baths, but even if they did you will require a blood transfusion.
-Dogs steal your lunch when you're not looking. Cats catch pests and present them to you as gifts. I hope you like dead mice on your doorstep!
-Dogs are for people who have low self esteem and must constantly be convinced they are needed or have a purpose. Cats are for fiercely independent people who are suspicious of everyone and everything.
-You must throw the ball to entertain the dog. This is why God invented "Outside", which is where the noisy, smelly, annoying dog belongs. A Cat will toss around the ball itself, it doesn't need you to play.
-You do not have to clean up the dogs vomit because it will eat it again. You must wait for cat vomit to dry and it will be kitty kibble again thus simplifying clean up. Unless the dog eats it first.