Whenever you start with PPC (Pay Per Click) Ads, you have to keep in mind the business goal or objective for running the Ad Campaign.
Well, there are three types of Bidding strategies as follows:
1. Cost Per Click (CPC) Bidding
2. Cost Per Impressions (CPM) Bidding
3. Cost Per Acquisition (CPA) Bidding
1. Cost-Per-Click(CPC) Bidding:
There are two types of CPC Bidding
a.) Automatic CPC Bidding: I personally recommend Automatic Bidding because it is simplest and most common. Set a daily budget & AdWords automatically manages bids to bring the most clicks possible.
b.) Manual CPC Bidding: It is the default strategy to manage max. Set different bid for each ad group in campaign, or keywords, placements.
2. Cost-Per-Impression (CPM) Bidding:
CPM Bidding focuses on visibility of ads to increase awareness about brand/product. I would suggest to make use of Facebook Advert instead of using CPM Bidding.
3. Cost-Per-Acquisition (CPA) Bidding:
CPA Bidding is used when campaign is direct-response related. For ex, campaign focuses on sign-ups or sales.
Three factors required when using CPA Bidding:
a.) Enable conversion tracking.
b.) Campaign received at least 15 conversions in the last 30 days.
c.) AdWords system requires this conversion history in order to make accurate predictions about future conversion rate.
Well, I would like to conclude with this, Depending on which networks your campaign is targeting, and whether you want to focus on getting Clicks, Impressions, or Conversions, you can determine which strategy is best for you.