That’s not the exact wording of the question that Vilma sent in last week, but it’s the essence of her question in five words. It’s a short email she sent, so I’ll just post the whole thing, no editing required:

I am starting a new business as a wedding planner. On google maps one wedding planner’s name only comes up now, but last week it was many of them. Why would google delete all the others and just keep one name listed in a big city?

This is a great question, and speaks to the fact that there’s a lot of confusion about the Hows and Whys when it comes to Google Maps. Vilma — let me try to break this down into different parts before turning it over to other readers to chime in.

1.) Search results change regularly. This is the first thing to understand. It’s not at all unusual for the SERPs (search engine results pages) to change from day-to-day, sometimes hour-to-hour, and sometimes even more frequently than that.

2.) Local search results are very much a work in progress. All of the search engines are constantly developing and trying to improve their local search results. On some of my favorite test queries, I frequently see exactly what you described — one week I might see ten local results with a map (the “ten pack”), and other times I might only see three local results with a map. Within the last week, I was surprised to not see local results (nor a map) at all on what were clearly local searches.

So, those are the two general things worth knowing. In your specific case, Vilma, it’s not that Google deleted the other businesses that you saw last week. It’s something else. You didn’t share the search term you were using, so this is somewhat of a guess … but it sounds like one of these things is happening:

• Google is testing different results displays, and using click-through data to decide if they should show one business or the ten-pack for this search query you used.
• Google isn’t sure if the search query you used was more likely to be a search for a certain business, or for a set of businesses. If you own a business called “Atlanta Dry Cleaners”, there’s a chance Google will show only your business when someone searches for “atlanta dry cleaners” or “atlanta dry cleaning.” When there’s an exact match like that, or when Google has reason to believe that a single business is a close match for your search terms, you might only see one business listed instead of many.
• The one business you saw might be optimizing for that exact term you used when searching, and through various means (perhaps some that are unethical), it may have tricked Google into thinking that it’s the single, authoritative match for a search query like yours that should actually be showing many businesses.

I hope that’s not too technical, and I’ll invite any regular readers to add their thoughts in the comments. Folks — how would you answer Vilma’s question?