Why Was Mini USB Deprecated in Favor of Micro USB?

By way of example – a number of Motorola’s “Razr” cellphones used micro-USB receptacles, thus allowing the designs to be thinner than would have been possible with a Mini-USB receptacle. A significant driver to a common USB connector is the new USB charging standard which is being adopted by all cellphone makers. Large list of cellphones that use micro-USB receptacle

A few more images allowing comparisons of a range of aspects including thickness, area of panel, overall volume (all being important independently of the others to some for various reasons) and retention means.

Source: electronics.stackexchange.com