Shared hosting is usualy only one option for most of internet users and webmasters. It’s biggest advantage is low cost, but there is a big cost in speed.
I have for example problems with my web, when it loades first. Server loads data from database, from your disk space and sometimes your special settings. This is the worst nightmare.
Web servers work like: Is file (database) often used? Keep it in memory, serve it immediately. Or – hide it somewhere and use it only in few special cases. But if Mr. Google visit your page, Mr. Google should think, that it is slow.
So, if you using shared server, make sure, that your page will be used as much as possible. In other case, you are almost doomed. This is not nice for you, but it eliminates “dead pages”. Mr. Google will ignore you, because you have no visitors.