Ad Serving is a reference to Pay-Per-Click (PPC) Ads.
Listing Serving is a reference to a Organic Result in the SERP’s.

Let’s say you are spending $10,000 on a specific keyword phrase per month, and it’s delivering a great ROI. Question is, should you divert some or all of that money to a SEO Campaign?

Here are some things to consider:
1) Using PPC, your Ad is only served while you still have a daily budget. Once your budget runs out, your ad stops being served.
2) Additionally, your PPC ad is probably not being served 100% of the time. Versus SEO, which is served 100% of the time. If your natural listing was organically being served in the Natural Results, your listing would be served 100% of the time.
3) Are you getting the maximum amount of visitors in the PPC results. Absolutely not. Industry Research shows that 72% of the clicks are on the Natural listings in Google.
4) People trust the Natural Results more.

What if optimizing for a Top 3 Ranking for that specific keyword phrase costs $5,000/month, and you just got the same amount of Revenue/Profits?

You’d effectively be cutting your advertising budget (for that keyword) by 50%, but not the Revenue!

The research slides can be viewed in an SEO Tutorial Presentation (Opens Powerpoint), I created awhile ago.

For a keyword that you don’t have any track record of advertising, then you’ll need to Calculate the Risk/Benefit by conducting:
1) Keyword Research
2) Keyword Analysis
3) Keyword Ranking
4) Keyword Traffic Reports
5) Keyword Demand Matrix (Proprietary - will explain in an upcoming post)
6) Analysis of Top 10 Results in the SERP’s.

Related posts:

1. How Much Work Should You Giveaway in a SEO Proposal
2. 10 Tactics for Video Optimization