Yes! And those robots are going to buy a lot more stuff from them..
/----/ Robots do have expendable parts and software updates. They are not without costs. Someone has to manufacture, sell, diagnosis, install and maintain these parts on a regular basis. Humans needed to provide these skills.
A definitive list of the parts that will fail over time on the robots.
Gear box: Needs vic's bearing mod otherwise it will eventually fail.
Brush: Only needs to be replaced once every 6-9 months
Beater: The rubber can tear if the roomba encounters rough obstacles but probably only needs to be replaced as often as the brush.
Side brush: Arms can break after 3-4 weeks of normal usage but there are ways to reattach them. Even if the arms didn't break off, I imagine the 'fishing line' would permanently bend over time and become less effective. Maybe replace the brush every 2-3 months.
Filter: Should replace it every 2-3 months to make sure it's effectively filtering out small bits.
Wheels: The wheels are made of some foam rubber or plastic and looks like it could will wear down rather fast. Probably needs replacing every 1-3 months?