It seems that Google is still having problems excluding Robots from their Analytics statistics. Robots are automated “crawlers” that are indexing websites, usually for search engines – they are not real live users so can bias your site usage statistics.
Previously Semalt.com was the main robot Google was trying to exclude. We monitor our clients’ Analytics stats regularly and have also identified unwanted visits from 7makemoney.com and buttons-for-website.com. Urlopener is another that is appearing (this is not really a robot but it is not wanted in stats data).
For one client, visits from these robots has amounted to almost 1/3 of their recorded traffic in a period, while for some other clients it is minimal. It can vary from month to month.
We are adding manual filters for these for clients in order to keep their statistics as accurate and meaningful as possible. But there is a limit to how many filters are worth adding or are reasonable to do.
Google needs to find a way to resolve this before their statistics become really meaningless. In the meantime we can help you to exclude these robots if you wish.