My first question would be is there a market for this business? Is it something that your customers typically buy with your current products or services or is it something they are asking if you offer?
Starting out, I would say to "test and measure" the idea with your current customer base to make sure it is a service or a product they really want to buy.
Then, add it as an additional service or as part of a "package" of services you offer and this package may be at a price point slightly higher than you are currently charging.
Test first before committing resources and marketing dollars and efforts to generating more leads to a new business.
You have the advantage right now (at least it sounds like it) of a "captured" base of current customers. Go back to them first. You already have a relationship with them and a reputation for your work.
Grow your "start-up" from this base, and you'll have a better idea of your new idea is a winner, and deserving of its own unique company.
Brad Sugars is the founder and chairman of ActionCOACH. As an entrepreneur, author and business coach, he has owned and operated more than two dozen companies including his main company, ActionCOACH, which has more than 1,000 offices in 34 countries.