http://www.iab.net/insights_research/ind...
Study: Global Online Ad Revenue to Hit $143 Billion by 2017
http://www.digitaltrends.com/web/online-...
I have been quite successful using 10-20 keywords per Ad grouping. Really, any more keywords than that and you'll most likely damage quality score and decrease your sales. I get quite aggressive in terms of increasing conversions by continually building out new groupings based on the competitors. Below is my contact info, email me (or give me a quick call), and I'll spend time with whomever brainstorming a few other quick ways you could increase ROI in your account. My email is simon.b@resultsdriven.org or my cell is 256-398-3835
It is mindblowingly huge! Depending on how many clicks a page gets the ads can be extremely expensive!
Very
