Pardon my extreme ignorance but I am a programmer and have little experience when it comes to this. Basically I am starting a site - for the sake of discussion lets assume it is similar to serverfault or stackoverflow (although my project is completely different, it could potentially, or at least I hope, have similar hardware requirement..in terms of bandwidth, storage etc.).
I currently have a simple ($10/month) shared hosting plan providing "unlimited bandwidth and storage". For development purposes, this has worked just fine. However, my question is this (I know its rather arbitrary): how soon and at what point does a site outgrow such a hosting plan? Assuming its a blog type website (or something similar to serverfault) after how many posts or after how much traffic would a dedicated solution be absolutely necessary? I know it sounds rather clowny to be asking about running a business off of a shared plan, but as I do not have experience dealing with such scalability issues I am rather clueless. Thanks.