I think that every successful product requires a strong vision. Start out small (MVP) and build on that vision. If you follow that path implementing "small" user requested features will most of the time be straightforward and will actually build on your initial vision of the final product.

However, sometimes you have to ignore some requests (big or small) if they aren't in line with what you want the product to eventually be.

One last thought is pivoting - which only select companies have managed to pull off - and have profited incredibly (Flickr, Groupon, PayPal). While it's not necessarily on topic, it's important to listen to user feedback and look for potential in every single idea (no matter how silly they might be).