Money & metrics · also called earnings per click
EPC (earnings per click)
EPC is average earnings per click sent, a term borrowed from affiliate marketing that trackers use for revenue divided by clicks.
Earnings per click comes from affiliate marketing, where it means commission earned for every click sent to a merchant. Trackers such as Voluum, RedTrack and ClickFlare grew up in that world, so their reports say EPC where a feed report would say RPC.
In search arbitrage EPC is used at whatever level the tracker can attach revenue to: per campaign, per ad, per placement, and per keyword. ClickFlare, for example, advertises "EPC per keyword" for search feeds. The comparison is always the same: EPC against the cost per click at that level. If an ad's EPC is $0.27 and its CPC is $0.20, it earns 7 cents a click.
Two cautions. EPC inherits the denominator problem of RPC, so confirm whether "click" means a bought visit or a click on a keyword. And the earnings behind it are usually estimated revenue, spread across clicks by the tracker's own model, because Google's feeds do not report revenue for each individual click. Treat small-sample EPCs as rough.
An example
Say keyword A received 300 clicks on the lander and earned $210: EPC $0.70. Keyword B received 300 and earned $60: EPC $0.20. Featuring A more prominently should raise revenue per visit.
Related terms
RPC (revenue per click)
RPC is the average revenue earned per monetised (paid ad) click: the "sell" price in search arbitrage. Convert it to revenue per visitor (RPV) before comparing it with CPC.
RPV (revenue per visit)
RPV is total revenue divided by the number of visits to the landing page, showing what one arriving visitor is worth on average.
Keyword-level reporting
Keyword-level reporting breaks down clicks and revenue by the individual keyword or related search term the visitor clicked on the landing page.
Tracker (campaign tracking platform)
A tracker is software that records every click an arbitrageur buys, matches it to the revenue it later earns, and reports profit by campaign, ad and keyword.
CPC (cost per click)
CPC is the price paid for one click on an ad; in search arbitrage it is what the arbitrageur pays a traffic source for each visitor.
Sources: ClickFlare: Search arbitrage tracking, ClickFlare: What is RSOC and how does it work