Google is on course to make more than $70bn in revenue this year, and much of that number will be generated by its insanely successful advertising business.

Advertisers pay a fee every time somebody clicks on a link in one of their ads. Some of the costs per click being paid are absolutely staggering. Though they must be worth it, from the advertiser’s perspective.

Last month I analysed Google Adwords data from SEMrush to discover the most expensive keywords in the UK. This time, I’ll be looking at the US.

So, here are the top 100 terms, taken from a massive dataset of 80m keywords…

Some themes from the research

The legal sector dominates

The most expensive term is closing in on a truly incredible $1,000 per click.

This may sound insane, but consider that the average mesothelioma settlement is in excess of $1m and it starts to make more sense.

Legal terms account for 78% of the top 100, and nine of the top 10. Big money.

Water damage

This is another big ticket item, with more than $250 per click for the top terms. It make sense though. as repair costs and associated claims can run into the tens of thousands.

Popular sectors

Other sectors that need to spend big to make an impression include Finance (insurance mainly), B2B (business telephony dominates here) and Health (the top terms being linked to rehab).

US and UK comparisons

One of the most obvious difference between the keyword costs for the UK and US is the absence of any terms related to gambling in the States, where it remains illegal to gamble online.

Gambling terms accounted for 77% of the UK’s top 100 terms, with the most expensive cost per click coming in at around $220.

The other thing is the lack of typos. In the UK advertisers are quite happy to seek out people who cannot spell, something that makes the eyes narrow when those terms are linked to gambling.

Sector by sector

Here’s the top five most expensive terms in the US, broken down by sector.  I’ve also adjusted the scale for each one, such is the variance in click costs between industries.

You can share these charts individually, should you wish to do so.

As Google continues to turn the screw towards a fully fledged pay-to-play model my bet is that we’ll see even more keyword inflation over the next few years, though ultimately there may be a point at which things start to plateau.

What do you think? Are you surprised by the amount being spent by advertisers? Do leave a comment below…