You’ll want to capture users’ emails regularly, both when they purchase…and even before they become a customer. You can use lead magnets or discounts to incentivize email sign-ups and using an email management service like MailChimp allows you to create triggered autoresponders that will automatically send out pre-made welcome email campaigns when they subscribe.
A good amount of marketing on the internet can be done for free, but sometimes it's worth spending some money on effective and professional looking options. For example, although you can get free web hosting, it's not recommended. Ideally, you should pay for web hosting to make sure that your website doesn't experience downtime, as well as a professional domain name. Fortunately, you can buy both for less than $100 a year.
Mechanical Turk is Amazon's take on micro-jobs. These are small miniscule-jobs that you can do for other people, which they call HITs, or Human Intelligence Tasks. These are super simple tasks that anyone can do. Some examples are listing off some URLs with certain kinds of images for one cent, or recording a few phrases with a microphone for 6 cents.