This bubble chart visualizes the relationship between marketing spend, revenue, and employee count for ten smartphone brands using a scatter plot with bubble size encoding employee numbers. The D3.js v7 implementation uses `d3.scaleLinear` for axes, `d3.scaleSqrt` for bubble radius, and `d3.scaleOrdinal` with the `d3.schemeSet3` color palette for brand differentiation. Interactive tooltips appear on hover, showing detailed metrics for each brand, while a legend identifies colors. Data is loaded from a CSV file using `d3.csv`.