The difference for me is Facebook is how I communicate with people I know, and Twitter with people I don't. To me they are different things. Of course not for everyone.

I like this analogy: Twitter intrinsically isn't Facebook, and it wouldn't make sense for it to try to be. Having that diversity in the marketplace is a good thing, and soft drinks demonstrate that such situations can absolutely be sustainable.

(Aside: if you make it Coke vs. 7-Up, you'll dodge that last complaint.)

I always considered Twitter to be a subset of Facebook, namely the status update.

> I know that Sprite is owned by Coca-Cola, the analogy doesn't run forever

It's a great analogy and I think it runs that far (that Twitter might be best served by becoming a subsidiary of a larger tech or media company).

A better analogy might be those smaller cola brands with higher caffeine levels. I don't know if you have these in the US; in Germany, there are a lot of them (e.g. Fritz Kola, Afri Cola, Club Mate Cola).

On the outside, it looks similar to Coke/Pepsi (still cola), but it has a vastly different and smaller audience (people who need caffeine, but despise the sugariness of energy drinks). But they stay in their niche, because any attempt to replicate Coke/Pepsi would get them crushed between those two.

maybe the analogy runs further than you think.. there's a lot of natural complements between these products, one is a runaway moneymaking success while the other product is more niche, but they can be sold/advertised together for bigger impact...why shouldn't they be owned by the same company?