Employees may not need bonus's or pay raises as much as they need recognition and connection (physical or emotional)
Motivation is like showering, you need to do it everyday or the benefit of a shower will soon wear off!
Human beings in general need to release certain hormones like oxytocin and dopamine. A personal thanks from their manager for a job well done or a high-five/pat on the back shows your workers that you support them, and encourages better performance.
Actually, The truth is there are several other ways to motivate employees and It is rarely money (even if they say it is).
Some Employee's want quality time with their managers, some employee's want recognition by their peers, some want gifts, some want act's of service like helping their finish a few tasks like picking up their dry cleaning or bringing them a coffee or lunch.
Let me ask you a question. If you were on a boat and it was sinking and there were sharks in the water waiting for you, and someone offered you $500 dollars to jump in the water would you do it? Not likely! (its not the money)
If you trusted the leadership and they were already in the water and said its safe would you jump in. (It's a little more likely)
However, if you watched your leadership get in the water and safely make it to shore, and bring another team member along with them came back and asked you to get in the water. Would you get in now? (maybe more likely)
It is important to never ask a team member to do something you wouldn't do yourself. Leading by example and providing your company with a crystal clear vision prior to asking them to do something scary (like jumping into the water with a bunch of sharks) allows employees to trust that their leadership has their best interest in mind.
So demonstrate that the water is safe, and paint the picture for them before they get into the water. Show them what is in the future ahead for them if they do what might be scary now.
Motivation dies out over time, but a vivid vision that allows a team member to discover their spot on the team will create a culture where anything is possible.
Some bustiness owners struggle with hiring or building their team because they are looking for a silver bullet to motivate their team members there are at 3 things I believe make a much better foundation before you begin to lead your team.
1. Have a vision.
2. Build Trust.
3. Create processes that allow them to fail their way forward while feeling secure that it is okay to make mistakes as long as they learn from them!
Lastly the end of your question states how to get employees to stay longer. There are ways to create golden handcuffs for employees by offering them profit shares, or doing an ESOP (employee-ownership program) However I would never want a team member to stay longer than they would want to be there on their own. I would focus on building a company culture that celebrates the big wins of the team.
I created an online course called build your million dollar team that breaks down 20+ Lessons on how to motivate and lead your team. Over 200+ businesses have used this to reshape their culture and generate millions of dollars. https://mitchdurfee.com/build-your-million-dollar-team/