Google My Maps is free, familiar, and very capable for what it was built to do: custom maps on top of Google's base maps and satellite imagery. Anyone with a Google account can drop pins, draw lines and shapes, color-code by category, and group items into layers. You can import a spreadsheet (CSV, XLSX, or Google Sheets) or a KML file, share a link, give teammates edit access, and embed the map on a website with an iframe. That's why so many outdoor festivals, county fairs, farmers' markets, street fairs, and car shows use it to show where food trucks, artisans, stages, restrooms, and parking are. Outdoors, on a real satellite view, it works.
The limits show up when your vendor map needs to work as a floor plan. My Maps has no indoor floor plans, so the moment part of your event moves into an exhibition hall, barn, or convention center, you're back to a PDF. A pin marks a point, not a booth, so there's no booth inventory, no booth sizes, and no "available / reserved / sold" status. Vendors can't reserve or pay for a spot on the map, and they can't update their own listing unless you give them edit rights to the whole map. Booth status still lives in a spreadsheet. And My Maps has documented limits on layers and on the number of rows per import, which matter as your event grows.
This page is for organizers who pin their vendors in Google My Maps and are looking for a Google My Maps alternative for trade show floor plans, festival vendor maps, and fair and market booth layouts. Google My Maps is free, and we say so plainly. The question is whether a free pin map is still the right tool once you're selling booths and handling hundreds of vendors.