Here's the difference between being an independent and purchasing a franchise...
With a franchise, you are given a turn-key business model, along with marketing support, but on the downside you need to do everything "their" way. For some people that is great...they would rather clean and work with clients than re-invent the wheel.
A franchise will cost you money, not only upfront but in fees along the way.
I am a very independent person, and knew I wouldn't be happy with the constraints of a franchise, and I enjoy the creative process, so I opted to be independent. The downside to that is...you really do have to put alot of work into everything from basic procedures to marketing and managing. It is necessary to do a great deal of research. The upside...the business is stamped with your unique brand and style, and you get to keep all your profits
It is a very individual decision...something that you need to make based on your understanding of your strengths and weaknesses, and how you want to spend your time.
On a side note, we have 2 housecleaning franchises in my area. I get the calls from the people who were NOT happy with the franchises...and there are plenty who aren't. It is vitally important to realize that homeowners only want to see the same faces over and over again in their homes..they do NOT want different staff coming in all the time. Whichever way you decide to go...keep this in mind.
Best of luck!