Like Michael Jackson, Prince also wanted to achieve commercial success since the beginning of his career when he released his ‘For You’ debut album in 1978.
With his next three albums he also aimed at commercial success (‘Prince’, Dirty Mind’, and ‘Controversy’
, that is why he toured those years in order to promote those first, four albums.
His later albums, such as ‘Purple Rain’ (1984), ‘Sign O’ The Times' (1987), ‘Batman’ (1989), ‘Diamonds And Pearls' (1991) were also albums with commercial success and a mainstream appeal.
Some contractual issues that arose in the 90s between him and Warner Records did have a negative effect on the commercial success of his albums released during that period mainly due to inadequate promotion (‘The Gold Experience’ in 1995 is an example, although its lead single ‘The Most Beautiful Girl In The World’ achieved tremendous commercial and chart success at that time).
In 1999, he achieved again commercial success with his ‘Rave Un2 The Joy Fantastic’, a mainstream album aimed mainly at the pop market and for that reason it included guest appearances from some successful at the time pop artists.
In that regard, the main differences between Michael Jackson and Prince were:
Firstly, Michael Jackson was totally obsessed with commercial success and he could not live without being commercially successful.
Secondly, Michael Jackson’s concerts were far more organized and much better promoted than Prince’s ones.
Thirdly, Michael Jackson had an entire, very effective machine behind him that enabled him to control and influence better the media, radio stations, etc, whenever he was about to release new music.
Lastly, Michael Jackson's music overall was more mainstream than Prince’s music.