What is the best way to start a WordPress blog cheap, but if it gets popular, scale it?

I used to recommend against http://WordPress.com because of the limitations they place on users to keep the servers safe for everyone. The theory was that you would quickly run into a wall where you would not be able to do things with the site that you really need to do. I now consider http://WordPress.com to be a very viable solution for starting up. You will definitely want get the premium domain and CSS options and may want to get a few other of the premium features. You will come out nearly the same price as many other solutions, but have a very stable environment where you can learn with less risk of killing your site. Also with WordPress you are never locked into a platform. The content is very easy to move. http://WordPress.com will scale to millions of visitor a day. You will not have to move for that reason, but will probably graduate as you start to consider features/design that are outside of what they offer. At that point you should be making enough to hire a professional team to move you to whatever host is the best at that time. Another great host at this time is Pagely, but "best host" status changes frequently as new competitors enter the field and great hosts of the previous year get too popular and fall apart under the load.

My advice would be rather unconventional, but this is how I started my site. I got a shared hosting account. If cost is an issue, then $3.95 / mo. wouldn't hurt a bit. Shared hosting only sucks when you start being a leech on the server (i.e consuming tons of resources). Otherwise, it is a great starting option. Move up to a VPS when you see you are getting some traction. Signup with a CDN and pay as you go. You can scale your VPS pretty well specially when the CDN is doing most of your heavy lifting. I use and recommend MaxCDN (disclaimer: although I'm not involved in the company, I know the guys, and they are awesome). If you don't know what is a CDN, then read this: http://www.wpbeginner.com/beginners-guide/why-you-need-a-cdn-for-your-wordpress-blog-infographic/ Now, if you are sure that this site is going to hit big, then you have to go about it differently. I knew my http://List25.com site was going to hit big fast, so I skipped the shared hosting step. Within 3 months, on our busiest day of traffic we served 4.5TB of bandwidth using MaxCDN for CDN and HostGator for server hosting.  The site did just fine. If you are not familiar with fine-tuning or don't want the hassle, then just pay WPEngine. They are a managed WordPress hosting who will help you scale as much as you need. Starts at $29 /mo.

It is easy to do.  I would start with the basics and get a shared hosting account, domain name, install, add content.  We cover the walkthrough of all of this at http://wpthink.com . Once you have that, you can scale it to whatever you want later.  You can just upgrade you hosting.  Hosting should only be about $5 per month to start out.  Hostgator is the host I recommend.  FYI.  Don't go with http://Wordpress.com, Do your own http://Wordpress.org installation.