What an excellent question! Now here's the "Fifty (OR MORE) Shades of Gray" answer:
If by "lifestyle" you mean a "Professional" taking appointments at a dungeon, caning one of the submissives from my stable while the rest of them are in various stages of suffering....the answer is no.
If by "lifestyle" you mean that I'm dominant in ALL everyday life situations with occasional participation in more structured opportunities, playing with others when the desire arises and adding experiences and gaining knowledge in my life involving the BDSM scene and my chosen partner/s....the answer is YES.
I've always been in control...in.....well everything. And I enjoy it this way. Every partner I have had is what has been termed a "service submissive." This person may or may not be dominant in their life...but when it comes to me, they do anything and everything to make me happy. They are fulfilled being in a "female led" relationship where their main concern is "What can I do to make YOU happy?" I'm there to take control of the situations in our life together. Everything from what type of hairstyle I'd like you to have; to who the waiter looks to for direction at our favorite restaurant. I don't have to demand or be pushy about it...you naturally submit and I step in and take lead. These people do not always see themselves as "submissive", but in truth they are. Understand that submissive doesn't equal weak!
These relationships are more about my desires, my needs being tended to...first and foremost and then my partner taking care of their needs. What makes it different than a "Professional" is that not EVERY day is a "scene" in our life. My partner brings me my coffee in bed just the way I like it because he wants to, not because it's on his list of chores. He's not wearing a collar to work everyday, but may wear one on occasion in the bedroom. He might engage in a cuckold or feminization experience because I ask him to do so.
Dominant is a natural state for me, it's what I find most comfortable and what satisfies me. I need to be in control of not only my life but my life with my partner. So yes while I may not be a "Professional" Mistress, I am without a doubt, a lifestyle domme and any man lucky enough to marry me one day must already subscribe to the "Happy Wife, Happy Life" philosophy.