Remarketing allows you to show ads to people who have previously visited your website or used your mobile app. When a visitor (potential customer) leaves your website without buying anything or completing an enquiry form, for example, remarketing helps you reconnect with them. This is done by showing relevant ads to them as they browse the web, as they use mobile apps, or as they search on Google.
Paid search is immediate in nature, your ads can be on page one of search engines within hours. Paid search can be highly effective if managed correctly. Costs can be controlled, sales tracked and revenue attributed easily.