Rider count difference - mobile app vs on screen

Today I noticed that the rider count listed on the main screen was  around +320.  On the mobile app, it had about the same number as I was logging in but once logged in, it said there were only 78 or so. Why the difference and which was more accurate?  Are ghost riders getting added to the count?  320 seems high for what I was seeing, but 78 seems low.

Also, the rider count on the mobile app was hard to see while people were chatting because the count kept getting covered up by the messages.

One other item related to rider count someone might have an answer to.  Sometimes the profile graph has very dense areas of riders and other areas with large gaps.  Is it that not all riders are being represented or are people really bunching up that much?

The app only shows you riders nearby (presumably by some radius). If you want to see riders further way, you can click on another rider in the rider list and wait for a few seconds for the server to send you riders close to that person. It seems like the mobile app only shows you the count of riders that are close where the main app shows you the total rider count.

The other thing to note on Watopia is that it appears like the server only sends information for a limited number of the closest riders, irrespective of which direction they’re going. This means when going reverse (where there are generally fewer riders) you sometimes may only see a handful of riders even though there are more riding. It can get to the point where it’s impossible to find all the riders that are riding reverse by clicking through the rider list because all the closest riders are riding the normal direction.