Stock sales is all about reputation and having the assets that are currently being looked for. It has for sure nothing to do with your region as nobody is aware of your region when scanning the stock database.
For having great sales on stock, you need to have a lot of assets. You need to have quality assets. The keywords need to be accurate. The title, even when not being taken into account by the search function on Adobe stock, needs to be accurate.
You will sell more by selling more which is by default harming newcomers. But I guess that new assets also get a boost by the search function. So it may be profitable to do regular uploads and not to put all assets on-line at the same time.
Other things that help boosting sales: assets with people are selling better than assets without. Getting the right time for the right theme helps. Christmas pictures will be acquired before the Christmas time, so posting a video of your Christmas tree now will rarely help your portfolio. Posting it next year, several months before Christmas may help. Doing series of the same subject with different angles will add to your chance to sell one of them.
BTW: This is the same for all stock providers...
Sent from my iPad