Raising levels is from higher level upvotes, this can come from even comments. That's why a good comment is powerful.

Higher level the person bosting you, the higher boost to the next level. There is a small down arrow near the payout of your post. It shows everyone who voted on your page, from highest investor to the lowest.

All my biggest payouts have Dtube listed as person with biggest investment into the system. Meaning all the Dtube upvotes raised me quick. The other votes didn't hurt by any means but I imagine Dtubes really helped. I hit 52 within a month, levels start to slow down then takes work to progress or huge votes.

Dtube gives back with the steam power they take as a cost to use the system. Dtube votes have huge value.