I also think that it is pretty normal to receive some increased amount of merits when you are close to your next rank. I have experienced this myself twice, once when I was about to become a full-member, @Royse sent me 15 merits for
this, and when I was about to become Sr.-member @theymo.s himself gave 10 merits to me for
this 
.
It is as simple as that, which is why I see no sense in the OP except that he had to make this post out of ignorance as being a newbie not knowing that users are likely to get inflow of merits when they are few merits to ranking up. It's a form of encouragement from other users especially from merit sources. I have had similar experience at the different points of ranking up. Perhaps @BD User should redirect his energy in building his account as he could also receive similar gesture in the future.