The comparison between shared and cloud hosting is like the comparison between shared hosting and VPS. Realistically I suggest you use whatever will fit your needs now without spending too much. It is nice with most cloud platforms that you can scale up as you need but most quality providers have an upgrade path as well.
I don't really recommend a cloud server / VPS unless you need to be able to customize the server or environment. In many cases you'll be able to do more with a cheap shared plan than you can a moderately expensive cloud server/VPS.