OP, Are you affiliated with coinmarketcap?
I still can't figure out how you ensure offering such a service. Can you provide more info confirming your credibility?
It's very easy, man. Create a giveaway and ask people to add X coin as the requirement to be the part of the giveaway. There are a lot of giveaway host who can do such easy job for only a few hundred USD. It's pretty easy and a lot of projects doing this.
If I understood you well, do you meant that the project (listed in cmc) contacted op (giveaway host) to do promotion via giveaway?
Even so, i don't expect a giveaway host promote a client project in the same way he is posting this poor topic. And for the most of times, this kind of promotion doesn't really bring satisfying results even for scammy projects.
As op is a newbie account, i thought it can be affiliated with cmc rather than being a giveaway host.