Also seems to me like they are replaced more often than conventional vacuums (more bugs, technical progress, they run more and thus are more likely to fail, ...)

There should be a Moores Law for cleaning robot since they are upgrading too fast that many people don't want to buy it too early.

I feel the opposite. I bought a Roomba 650 almost exactly four years ago (one of the best purchases I've ever made) for about 350 dollars after a bed bath and beyond coupon. With a little bit of maintenance it still runs every day exactly as well as it did the day I bought it.

The 650 is the robovacuum Sweethome recommends and has recommended for years (http://thesweethome.com/reviews/best-robot-vacuum). The newest Roombas since then have been mildly incremental, and the competitors have struggled to offer something that works better. One of my close friends bought the exact same model last week for 370 dollars.

That's not to say there isn't room for a lot of improvement, but I think it's been a super slow moving space.

I own a 880 and 760 and I could not be happier with both of them. I had the 760 for over a year, but it couldn't properly do my entire upstairs (its rather large). So I moved it to my two room downstairs and bought the 880. With the 880 it comes with lighthouses that signal the roomba to know to do each room separately. I can not be happier. The 880 was a great upgrade too, the brushes are easier than ever to clear and maintain (basically you don't have to).

Another Roomba 650 owner here! Mine was $280 purchased from eBay, in March.

I also have a Roomba 555 bought for $200 in 2012. I spent about $100 to upgrade the older one to the newer sweeper/dustbin and to buy a new battery.

Love them both! Could not imagine life without them. To press a button, leave, and come back to a parked Roomba with a full dustbin is glorious!

The amazing thing is that they actually do a better job then using a broom and dustpan.

I just got my first 650 yesterday. I was recommended away from the more expensive models because for a home as small as mine, the features didn't make sense for the price.

It's running right now, and with two dogs and a cat my floor is rarely ever this clean.

We don't need a Moore's Law. However, more robotic vacuums will generate revenue to further advance robotics research. Lawn mowers, leaf cleanup, etc.

We're waiting for the Apple II or iPhone 1 moment then things will get interesting.

If we assume a fixed lifetime of n years for vacuums, it will take at most n years to get to 20%.

If we assumed a half-life of n years, then robot vacuums will only ever approach 20% asymptotically and won't ever reach it.

(We could get over 20% if robot vacuums have a longer lifespan than regular vacuums. I'm tempted to write a simulation over different failure curves but I really have better things to do.)

> If we assumed a half-life of n years, then robot vacuums will only ever approach 20% asymptotically and won't ever reach it.

You shouldn't assume that they will be 20% of sales for every future year.

Not sure if you have ever met a Tellus vacuum cleaner, but as far as O can tell they live for ever and bugger up this equation.

I would guess robot vacuums have a shorter life! I'm still using the same vacuum I grew up with, it's more than 20 years old and going strong.

Even with the caveat that they mean only vacuums sold this year the number seems off. There are about 20 million sold each year in the US alone[1]. Assuming 20 times that worldwide, that's 80 million robot vacuum cleaners. If true that's an incredible level of sales for a product that's less than two decades old.

[1] https://business.highbeam.com/industry-reports/equipment/hou...

That's a good call for pointing out the logical flaw. But basically from the people I know who owned a cleaning robot, generally it last no more than 2 years because of the new technology and the battery life.

Also because of the amount of problems it has, and the er... "limited" quality of the result, people hope that it improves with the next versions.

And I'd add to that: in the USA (with a bit of extrapolation).