When you're new to the game and your level is pretty low the consecutive days bonus is great, it makes a huge difference. Once you get to a big number it becomes a bit pointless.
It seems they didn't really think it through when it comes to levels and the gaps between them, just look at the objectives. Play Blitz on BPB and earn 10xp. Yeah right, with over a quarter million to the next level I'm gonna play a stupid Blitz game for 10 points. Make it 2k or so and I might think about it.
On the other hand at least they carry on adding to your level, I recently stopped playing an online game that stopped at level 60. You still saw how far you were from the next level and got a bonus when it happened but your level never actually showed higher than 60.