Been a user for several years, and had no problems. Discovered fairly late that MacKeeper had not been working since "license" had expired. Tried to renew, and had to contact support for proper activation, and ended up upgrading to Mac service along with MacKeeper. They cleaned and streamlined my computer so that it now works like new, not like the senior grand dame that she is (early 2011 MacBook Pro). Here's to another 2 years of hassle-free computer use!