A Conversion is any user action that you want to measure, such as a signup for a newsletter, completely a purchase, or filling out a web form.

CPM is an acronym for Cost-Per-Thousand. Many online ads are priced on a CPM basis in which the cost is expressed for 1000 impressions. E.g. If a banner advertisement is placed at the price of $20/M then the CPM is $20, or $20 for 1000 impressions. Most search engine ads charge based on the number of ad clicks (PPC) instead of impressions.

CPR may refer to: Cost Per Registration Cost Per Revenue

CTR, or Click Through Rate, is the fraction of users who click on a keyword advertisement to those that view that advertisement (an impression). CTR is usually expressed as a percentage.

Google Bombing refers to the practice of creating a large number of links with specific keywords in the anchor text to rate a site very highly for that keyword. For instance, one of the most successful Google bombs resulting in the top Google result for "miserable failure" to be the Presidential home page of the white house during the fir [..]

Google Sandbox refers to a hypothetical mechanism that factors a website's age (or lack thereof) into its ranking on popular keywords. Around the end of 2004, many website developers started noticing that sites that previously took 4-8 weeks to get indexed and ranked by Google were suddenly taking much longer. People surmised that Google pu [..]

An impression is a single display of a particular ad on a web page. Some search engine advertising fees are based upon the number of impressions, while the majority are based upon the number of clicks (PPC).

Impression Share (IS) refers to fraction of total searches for set of keywords are being shown your ads. For instance, you might have enough budget to pay for 1000 impressions per day in a PPC campaign, but there 2000 people searching every day on your target keywords. Your Impression Share would be 1000 / 2000 = 50%. In this simple case, you could [..]

A search engine index is a database that correlates keywords and websites so that the search engine can display websites that match a user's search query. See also indexing.

Indexing is the process of building a search engine index. Technically, indexing is a separate step from assigning keyword rankings.