These in-ear buds are probably just about fine for making phone calls with the benefit of the buds staying in your ears. These are not, though, something that I would recommend for music or spoken word. The caps are very poor, but even when I replaced them with others I have, the lack of clarity meant that I had to have the volume up pretty loud to understand what was being said.
Conclusion: if you find the iPhone standard buds fall out and you intend to use this just for phone conversations in reasonably quiet environments, then go for it: they are remarkably cheap. Otherwise, look elsewhere and pay a bit more for the sake of your hearing.