In my opinion, I would consider your long-term goals. If your plan is to build a brand around yourself and become established as a major influencer, it certainly makes more sense to go that route. On the flip side, your low hanging fruit is to build a brand around the concept by which you intend...
If I had to start over, I would have built my email list of raving fans first. I was already published on Amazon, B&N, Kobo, and iBooks, but I gained traction by having a readership of peeps on my mailing list who I could contact every time I had a book ready for release. Something I've learned...