Over the years I've noticed something in products, from chips to movies, if someone else does it, you can do it cheaper and make money. Is the big movie company selling Alice in Wonderland for too much? Pay $5 and get Alicia in Wunderlund instead. Snakes on a Plane? Try Snakes on a Train. Kool-aid drink mix costs too much? Buy the cheap store brand.
This goes on to Tablets, dish soap, and all other things. Including video games. But in the case of video games, no one wants to pay for a bad game. Where a bad movie can have a certain appeal (there are people who only watch B movies), someone who plays only B games (60 on a metacritic score or lower), would instead be depriving themselves of quality and fun (unless the game happens to be niche).
So with game design, you can't necessarily think, I'll make a game that is less fun, and still make money. Unfortunately, people imitate another game, and all you have is the same game with perhaps less graphics, or missing that one really cool mechanic. Usually, you are disappointed, and realize you should have just spent the extra $15 on getting the good game.
Perhaps, if a game follows the idea of investing less graphics, or less sound quality (music, sound effects, etc.) they can make a game that is equal in fun or perhaps even more fun. In this case, they need word of mouth for people to go, hey, this game is cheap and more fun. I'll invest in that!
But to drag someone away from the heavier investment though, amazingly takes more work. That person's social graph needs to be following the cheaper, less impressive looking, but more fun game, to get to them. Don't forget they have time and money invested in the more expensive but slightly less fun product.
What if a company invests more money into their "me too" game? So that graphics, sound, and fun are in greater proportions, and they make the game equal in price or even higher. Don't forget, up to a point, people perceive price as a measure of quality. Although people want things cheap, they will invest into something that seems of better quality.
In this case, most people who are still happy with the first game, wait to see the results of this new game. Did people like it? Was there a bunch of bugs? Is it worth their time? Are their friends playing it?
People think that once a product reaches a certain point, then there is no way to dislodge it. But, at some point, you need competition. In the case of iPhone and iPad, the Android is creating serious competition. In the case of Google search, the competition has 40% of the remainder (meaning that though Google is on top, they are not the only search engine). The same is true for World of Warcraft. For years their numbers have remained about the same. Yet only 10% of all accounts make it past level 10. That means that 90% quit. 11.5 million is only 10% of all people who have tried WoW. Either that, or gold sellers have made 90 million WoW accounts.
So far, "me too" game design has not worked on gaining market share against WoW. Its competitors have had to switch to a different model. Perhaps, they were not different enough. Much like dealing with Facebook, some sort of revolution in the social graph would be required to take people from WoW. Failing to do so, everyone else should instead, look to working around WoW, and compete in that F2P micro-transaction area.