Casinos and sports betting sites offer incentives for new customers to open accounts and the site could be geared around documenting the current offers available and then making a commision on referring those customers. The content could be based upon upcoming sporting events. The site would essentially be a one stop place to view the offers available. - gamblingsource - a source for gambling.
you could make a gambling portal from it as you say but as a domain by itself, I dont see much value. Develop it get some traffic on it and try selling it then.