How to go about selling your online business?

me and couple of friends started a website as a side project. all 3 of us work fulltime so the website basically runs itself. over the past few years we've had amazing growth with $0 spent on marketing or advertising where our competitors get lots of media attention and do lots of advertising.

we went from making $1000 a year to now over 100K/year. what can we do in order to see if there is any potential buyers interested?

thanks