This past Friday, Amazon announced its intention to buy iRobot, best known for its Roomba vacuum cleaner, for $1.7 billion. In describing the deal, Amazon’s hardware chief applauded iRobot’s “ability to reinvent how people clean with products that are incredibly practical and inventive…” This may make some people think that Amazon wants to go after Dyson for having the best vacuum cleaner on the market. There’s much more to the story. The…