In some parts of the world, notably the North American continent, one cannot expect SMS between carriers to work properly; there are many missing routes, including where there is a route from carrier A to carrier B but not from B to A so you can't get a reply to your SMS. Also even when it works it can be very slow, transit times of hours are within my experience.
It's not like Europe where SMS can be expected to work so well that it effectively always works and is fast.
Of course the North American telcos still charge you for your SMS when it disappears into hyperspace because their network isn't configured properly, but I'm sure you all expected that.

While it is true that SMS is carried in the control channel of GSM [1] and that control channel has reserved bandwidth not available for voice call channels, it is also true that heavy SMS traffic will saturate this control channel and that some carriers have had to increase the control channel bandwidth in order to make room for the volume of SMS. You can observe the control channel saturation (and resulting inability to set up new calls, while existing calls continue fine) in any major city in the UK from around 23:45 on 31 December to 00:30 on 1st January. So the carriers do have to put a bit more bandwidth into lots of SMS.
However there is also an SMS messaging centre to operate, which is a pile of computers to route messages, as well as storage on each cell base station for the SMS waiting to be transmitted to the handset - rather like email it's too cheap to meter, except for all those mail servers you need to forward and store the email.
The profit margin on SMS is clearly huge (consider that bulk SMS rates are at most half the cost of single SMS out-of-plan from a handset in the UK) but it's not 100% profit and 0% cost.

And finally, think about spam: the reason you don't get much SMS spam (compared to email) is that it costs quite a lot to send SMS compared to email. If you make SMS as cheap as email, you'll make it as spammy as email, and you need to think about how to avoid that.

[1] I'm going to ignore CDMA here, I wish the rest of the world would do the same.

This is an interesting test, but some market leaders are missing, notably Trend (El Reg quotes Gartner saying Trend has 13.8% market share, third after Symantec and McAfree). If I am to use this research to pick a solution or to pick a better solution, the chances are high that someone in the management is going to "suggest" (try to make me use...) "Trend" because they've heard of it; if they suggest "McAfee" I can use this research to shoot that down, but not Trend.
Meanwhile, to bang the open source drum, they also didn't test Clam AV. I don't know Clam's market share, but I have to say I like it a lot for its ease of integration into my UNIXy infrastructure compared to the commercial ones I've tried, and I consider it worth testing because of its different development methodology with undoubtedly different strengths and weaknesses compared to the big commercial AV vendors.
So it's all very interesting but not entirely useful to me.

Because they are friends of Microsoft and that makes them look like good lap dogs?

I've just checked my work's logs (an ISP). The number of hits in the spam taggers fell from 12/sec to 3/sec earlier this week.

So either we're identifying less spam, or there is in fact less of it.

Enough cicky-clack to annoy your workmates, and a good feel to it.

Never had a Model M, though, so I can't give a comparison.

Also, I only have slight problems with the lack of key information w.r.t. the top row (numbers and symbols on top). YMMV, of course.