Moving people from one much-loved service or product to its replacement is always a difficult task.
There may be strong corporate reasons for doing so, and even advantages for the consumers to make the shift.
However, the situation always risks turning into a 'New Coke'; an attempted product migration that has since become a model of what not to do.
Signs are good
The men behind Zynga's move to persuade the millions of happy players of Words With Friends to shift to New Words With Friends - tag line 'May The Best Friend Win' - don't appear to be suffering from such worries, however.
"It's been in soft launch for a while now and has the features players have been asking for," says Jonathan Knight, Zynga's VP, Games.
"New Words With Friends comes with more ways to play and more people to play with."
The most notable difference is the new look and feel; after all, the original game was released five years ago.
During that time, over 58 billion words have been played within the game, which has 55 million matches in-play at any moment and 1.4 million players using it daily as a game-come-chat/messaging service.
Indeed, Zynga is proud that 60 percent of players say they use the game to stay in touch with their family and friends.
But it's this committed fanbase that will provide the inertia Zynga will have to overcome if it wants to get New Words With Friends off the ground.
Of course, the original game will still be supported: both titles use the same backend so players who don't want to update won't notice any difference, other than regular prompts asking them to download the new app.
During the soft launch, we saw 20 percent better retention.Jonathan Knight
As for new features, these should encourage better retention and engagement.
For example, there's now an in-built dictionary and a word of the day. You can play offline, there's a Solo practice mode, and better personal stats in terms of win-loss rate, best words played etc.
There's also a Tinder-style Community mode which you can use to find random players to start games with.
"The user experience is better optimised for whatever device you're playing on," says Words With Friends GM Vaibhav Sahgal.
"In particular, we've focused on making the game list slicker with big profile photos and features so you can see which of your opponents are online."
Unsurprisingly, the designers haven't meddled with the game board - "It's the Holy Grail", says Sahgal - although they have tweaked board navigation.
Yet, assuming they can get players to make the jump, the signs for Zynga are good. After all, during a difficult 18 months, Words With Friends remains one of its key franchises.
"During the soft launch, we saw 20 percent better retention," says Knight, pointing out that given the game's ad-funded model, retention - and player satisfaction - remain key business indicators for Zynga.
New Words With Friends is out now on Google Play, the Apple App Store and Facebook.