Backlinks can be time-consuming to earn. New sites or those expanding their keyword footprint may find it difficult to know where to start when it comes to link building. That's where competitive backlink research comes in: By examining the backlink profile (the collection of pages and domains linking to a website) to a competitor that's already ranking well for your target keywords, you can gain insight about the link building that may have helped them. A tool like Link Explorer can help uncover these links so you can and target those domains in your own link building campaigns.
As advertisers collect data across multiple external websites about a user's online activity, they can create a detailed profile of the user's interests to deliver even more targeted advertising. This aggregation of data is called behavioral targeting. Advertisers can also target their audience by using contextual to deliver display ads related to the content of the web page where the ads appear.:118 Retargeting, behavioral targeting, and contextual advertising all are designed to increase an advertiser's return on investment, or ROI, over untargeted ads.
CPC (Cost Per Click) or PPC (Pay per click) means advertisers pay each time a user clicks on the ad. CPC advertising works well when advertisers want visitors to their sites, but it's a less accurate measurement for advertisers looking to build brand awareness. CPC's market share has grown each year since its introduction, eclipsing CPM to dominate two-thirds of all online advertising compensation methods.:18:1