My ISP just upgraded me to 6 MBit free of charge

I just got an email from my ISP NetCologne saying that they just upgraded me from 2 MBit to 6 MBit without extra charge. I immediately made a speedtest and reached ~550 KBit KByte/sec upon downloading a 10 MByte file. The theoretical maximum would be 768 KBit KByte/sec but with all the overhead a realistic value would be ~650 KBit KByte/sec. Maybe I should check the settings to see what those ~100 KBit KByte/sec fricitional loss attribute to. Anyway, thanks NetCologne!