They like the sex, the financial remuneration is icing on top of the cake.
Strangely enough he never actually stated what we now call the scientific principle named after him that says all things being equal, the simplest solution is likely to be the right one. http://Www.Historiasdeluz.es/con-luz-propia/en-el-exterior/noticias-andalucia-alvaro-martinez-citricos