- Ads show up in Google search results (or other websites which participate in the ad program)
- Ads are only shown when the user enters a specific search which you target. If you are selling leather shoes, your ad will only show people who search Google for leather shoes.
- You pay when someone clicks on your ad
- Ads show up on Facebook and Instagram
- Ads show up based on peoples interests or browsing activity (not when they directly search for specific products)
- You pay when your ad shows to people (not when it's clicked)
There are ways to advertise on Google without paying, SEO is the term. However, it takes a considerable amount of time to see the results.
You can advertise on Facebook and Instagram without directly paying for ads. You can either use other people (influencers) to advertise your product on their social feed or you can set up contests and let other people participate and share your posts.