Obviously it is not a scam, but their system is strange.
It looks like if you want to earn more than 1.50 euro per day you must purchase contract. Here is my 10 days experience with solo mining:

earning with 5.2 mhs miner per day = 1.50 - 1.55 per day no more
cointellect pool report correct miner hashrate on dashboard
 
earnings with 20 mhs miner per day  = 1.50 - 1.55 per day no more
cointellect pool report  incorrect miner hashrate on dashboard - 0.55 mhs max
I don't know why I am earning same amount of money for 20mhs and 5.2 mhs . This is weird. I did not contact them because I've got no response  last 5 mails that i sent to them... I was expecting around 4 eur per day ( they offer 25 mhs contract with estimate 5.50 eur per day)...

As user jawitech mentioned you can earn 1.50 euro with 1 mhs ( 3 days tested and works)

So better do not mine on cointellect with more than 1 mhs because it is waste of power.  Next week I will order their 25 mhs contract, so I will report here.

If anyone has info about solo mining earnings and especially why your earnings are equal with 20mhs and 1 mhs let us know.