Do you mean mingle or mingle2? They are both owned by the same company called Mingle LTD, at least according to the Google App store.
Mingle2 was the original dating site and open in 2006 and was free. It says it is owned by NextC LLC which I believe is a subsidiary of Mingle.
They also own JustSayHi, Fem, and over 50 other dating apps according to their website. These group of dating services are also refer to as Minglenet. At the app store just look for "Mingle Dating Social Network" and you will know you have reached one of their apps.
The overview says they have 20 million members and over 15 thousand users a day. Not sure if it is true or not...
Is it useful for dates? I so far have not had much luck.