It seems to be a good strategy when I'm in danger of throwing a temper tantrum. It seems to help with that all or nothing attitude so many of us struggle with. I didn't leave early enough to get to the gym for my full weight workout today, and I was tempted to scrap the whole thing, just because I was looking for my stupid heart rate monitor. Finally, I decided that I didn't need a gizmo to know how hard I wanted to work in my Spinning class, and I just went. I did about 15 minutes of weight training, which isn't as good as my planned 25-30, but it's a whole heck of a lot better than 0. If I had scrapped it, I am sure I'd also have been less likely to go next time. Now I still have my streak going.
A second strategy was that I convinced my husband to get up early with me in the mornings and do a 20-minute Pilates or yoga video. We're committed to two of each (which means we can pick one day to be lazy and sleep in). If I had decided to do this by myself, I think I would have slept in today, but since he was already awake, my husband got me out of bed too. And it was really not so bad, once I was in the vertical position.
I guess what I'm saying is that since I don't have killer willpower or motivation, I'm making do with flexibility, self-trickery, inertia, and a pestering spouse. We use what we've got, I guess.