Here are some examples, some based on personal experience.
- You could set up and configure an email server to send email to your users, or just use a service with an API like Mailgun or Mailchimp.
- You could write your own Wordpress theme and plugins from scratch, or just pay $10 for a slick theme and $50 for a few plugins that meet all your needs.
- You could spend time each week backing up your system with a set of external drives, or just pay a monthly fee to Crashplan or Dropbox.
- You could buy a discount VPS account and spend all your time keeping it patched and running, or just pay for a fully managed server until you outgrow it.
In each case, the former solution is "free," but may require you to spend tons of time getting it working and putting out fires. Often it's better to pay a little money to just remove the problem from your critical path. The reason for this is that you only have a finite amount of time and mental energy each day. Try to use them on the things that matter.
A specific example would be hiring someone to manage your server.
Some examples of the general principle I've used in my own business: upgrading to latest Macbook air, hiring a maid so I don't have to clean my home-office.
An example of what I think he means: When you get more traffic, you can buy a huge but cheap server from Hetzner, or you can just spin up more dynos on Heroku.
Can somebody please explain what he means by this using some examples? Thanks!