I'm sometimes asked to define what successful bivocational ministry looks like. My short (and financially inspired) answer is to recommend the questioner read my book The Bivocational Pastor. The working title for that book was Success in Bivocational Ministry which pretty much defines what the book was about. If a bivocational minister tries to define ministry success in terms of nickels and noses he or she isn't likely to feel very successful, but I believe there is much more to successful bivocational ministry than that.
For the bivocational minister success will be found in faithfulness. It is in recognizing that God has called you to this place of service and has asked you to be faithful in that service. Success is understanding that these people are persons for whom Jesus Christ gave His life and deserve the very best ministry you can provide them. It is in being willing to sow seed and allow God to give the increase and patiently waiting for that increase to come. Success is in being willing to watch others climb the ministry ladder of success moving every 2-3 years to a larger church because "God called them to this new place" while you remain in your current place of ministry. Success for the bivocational ministry is often found in being more concerned with what God thinks of your ministry than your peers. It is in knowing that you have chosen to serve this particular congregation for as long as God asks you to.
Successful bivocational ministry happens when you love the people you serve, when you maintain your passion for the ministry even when the numbers are few, and when you serve with integrity. You enjoy a successful ministry when you and your congregation discover God's vision for your church and you seek to live out that vision in your community. You will enjoy a successful ministry when long-time members of the church share painful experiences in their lives with you and then suddenly look at you in surprise and say, "You know, I never told another minister that." Your ministry will be successful when your church attempts to do something far larger than anything they have attempted in recent years because they trust your leadership. You will know your ministry was successful when someone you haven't seen since they were a small child asks to be your friend on Facebook because they remember when you were their pastor.
I hope this helps you define success for a bivocational minister, but I had to admit that I haven't scratched the surface. Just don't get caught up in nickels and noses or any of the things denominations consider as marks of successful ministry. You have been called to your place of service by God, and if you are faithful to that call your ministry is a success.