Company owners often receive approaches from firms (private equity and trade) who are interested in acquiring their businesses well in advance of the intended time horizon for a sale.
It is always flattering to receive such approaches and is an indication that others recognize your achievements and the quality of the business you have created. It also suggests that when the time does come to sell your business, you will have a number of parties who have already put their hands up as potential suitors. It is also a good dynamic when you do launch a sale process to have, as a reason for sale, the fact that you have received a number of approaches and that this has influenced your thinking behind the decision to put the company on the market.