Unfortunately, as website search engine optimisation becomes more and more competitive, top search engine ranks nowadays often go down to Google PageRank competition.
The requirements for high PageRank basically comes down to having well-constructed links (with proper keyword insertions) from high quality websites (with high PageRank).
If your website happens to own a good PageRank, there is a real opportunity to "selectively link" to other websites which desire this. In return, a "stipendium" in the form of your local currency is commonly exchanged.
I am not going into the tricks of offering such services here, but needless to say Search Engines frown upon the practice of Selling Links, so it may be preferable if you do not advertise such abominable thing on your website :)