There are only two main sites that users can choose from to play daily fantasy, DraftKings and FanDuel. Both sites share similarities but at the same time are drastically different. Both are similar in popularity and have been around since the beginning of daily fantasy sports. Both sites offer hundreds of contracts and pay out millions of dollars every day. The sites pay out at an identical rate and the contests offer the same rewards on both sites. So how do you choose which one to use?
The answer is pretty simple; try both of them out and choose which one you like more. Both sites will pay out the same. So, profitability and your chances of winning are basically undistinguishable between the two. The difference between the sites is how you build your lineup for your daily contests. For example, in daily NBA contests, on DraftKings you choose eight players and on FanDuel you choose nine players. DraftKings gives you a salary cap of $ 50,000, allowing you to choose eight players with combined territories of $ 50,000 or less. On FanDuel, you have a $ 60,000 salary cap to choose nine players to fit into your lineup. Salaries of each player are different on each site. A popular opinion is that you can have more superstars or more higher salaried players on FanDuel because of the higher salary cap. This may be true, but everyone else you are competing against also gets more superstars or better players so it does not really make a difference.
FanDuel's lineups are constructed of two point guards, two shooting guards, two small forwards, two power forwards, but only one center. DraftKings' lineups are constructed of one of each of the five positions (PG, SG, SF, PF, C) and then one guard, so you must choose a point or shooting guard, one forward, either a small or power forward, and then finally a "Utility" player (this mean you can choose any player at any position) So the main difference between the sites is the strategy you use to construct your lineups. I suggest going and playing around on both sites and seeing which one you like better.
I would suggest choosing one site and playing that one only, not both. The strategies are different for both sites so once you choose you will want to stick with one and perfect your own strategy of building daily lineups. Bouncing back and fourth between sites will just be more challenging and require more time and research. Once you figure out which site you want to use, use it everyday and perfect your own strategy. The more times you play and the more experience you gain in creating lineups, the better you will become. There is a skill in building these lineups daily and with all skills you have to practice them to get better.