Ok, so let me educate you on the online gambler.... since I have worked in the industry for 10 years.
The online gambling market is huge... many of the Vegas customers play online and have done for many years. You would have to be a complete moron to not assume that this industry is a perfect complement to your B&M casino. Let's just take lessons from Blockbusters/Netflix, Amazon and any book retailer... the list is endless.
Online gamblers have many different casinos to choose from, generally they are members at several casinos using different software. Once a customer feels comfortable with one or two casinos and their software, they generally stay.
The advantage that the B&M casinos have here is the ADDED security of gambling online with a recognised entity, that has a physical address that you can visit. It makes no sense employing a team of people to "develop" a software, particularly when there are several software developers making excellent casino software. Do casinos build their own roulette
tables or employ programmers to make slot machines? Of course not, they purchase these things from suppliers. The online casino extension will be no different. They may choose to take in-house certain elements, such as customer service, VIP management. Perhaps after a while they may take over more complicated elements such as the security and financial processing. The option also would be to purchase the software company and swallow up all the licensed casinos operating under that company and run the entire company for yourself. You have then just purchased all the skills you will ever need.