Whenever you’re looking for a new hosting company, you always need to know what you’re planning to do beforehand. You also need to communicate with the provider you’re thinking of going with beforehand to make sure that your project will be stable for their equipment. For the most part, these people don’t want to deal with you if your scripts are hogging up bandwidth because it only makes their other customers angry and more money being spent from their pockets.
For example, I wanted to pursue a podcast that reached 10,000 subscribers every week and that was 20MB in size. The host I approached said that it wasn’t a good idea, so they pointed me to another. That’s better than me having to find a new one after one month anyway.
With media files, you always want to go dedicated because of the size. If you’re an artist, filmmaker, or photographer, you’re most likely wanting to showcase your work in the best quality. Photographs are usually 2 to 5MB in size and shared hosting might not always be set to take it via something like WordPress. Otherwise, you’d have to do it manually. The fix would be to edit your php.ini which is only available in a dedicated server setting. Applications, forums, and any other site that requires registration is more suited to this type of server.
Shared servers should be used for small blogs and single page resumes or showcases. They’re mostly limited in size for that reason. Having 100 forums with 1,000 active members each will overload the server. So it’s not exactly the best setup.
So basically, if you want space to grow your own community, a dedicated server is the best. If you’re looking to operate a one man band with a small blog that won’t have much, then sharing is the better option.