I have a blog that was getting 100 K visitors per month and I hosted it on cloud hosting with 2 GB of ram and it worked just fine.
After awhile it started getting 200 K monthly visitors and now gets over 1 million monthly visitors and I have 16 GB of memory on the cloud hosting just in case the traffic goes up even higher so I'll be ready for it.
Although I'm sure the blog could be hosted with a little less ram but I just don't want to take the chance.
A good cloud hosting company and good hosting company overall is https://hawkhost.com
Once your blog starts getting traffic then standard shared hosting is not good enough to keep up with the traffic and you really should go with cloud hosting which you can easily scale the resources overtime really quick as the traffic grows.
Cloud Hosting is also faster and more secure and reliable than standard shared hosting or VPS hosting or even a single dedicated server.