Three English rugby union clubs have become the latest sports teams to launch 'fan token' schemes.

The 'fan token' concept has been used by several football teams in recent years and uses similar technology to crypto currencies to generate funds.

It has not been without controversy - in 2020 Premier League team West Ham United ended a deal with Socios after a backlash from fans who felt they were being unfairly "monetised".

What is the background?

Most football clubs in the market offer 'fan tokens' akin to club-specific crypto-currency - virtual coins can be bought and sold and their value rise and fall depending on supply and demand.

Fans that buy them are offered exclusive experiences, content and opportunities or rewards.

Among the initial offering from the new partnerships, Saracens fans can vote on the name of their new West Stand at the StoneX Stadium, Leicester supporters could spend a day with the Premiership trophy and Quins fans might get a chance to watch a game from the bench.

However, the schemes are not without their critics.

The very nature of the tokens means their value can fluctuate, and many have decreased since they were initially sold by the clubs.

Other critics highlight the scheme's use of blockchain, which uses large-scale computing power and energy-use to run.

What did the clubs say?

All three announced the news at the same time.

Saracens CEO Lucy Wray said she hoped the new offering would help provide fans with a "further way of getting closer to the club".

Leicester's head of business development Mark Davies said: "Technology is rapidly changing how sports fans want to interact with their clubs. The key is working with fans to ensure it's used in a way which benefits them, and that's why we're hugely excited about fan tokens."

And Harlequins' chief commercial officer Steve Morton said the club was committed to bringing all supporters "closer to the game via rewards and experiences".

How did fans react?

The Saracens Supporters' Association said it would not comment on a specific deal "at this time" but added: "We hope that all partnership and sponsorship deals have a positive impact on the club and fans alike."

Phil Gibson - the vice-chair of Quinssa, the official Harlequins Supporters' Association - told BBC Sport: "Generally speaking anything that allows supporters to build closer a relationship with the playing squad will be supported and encouraged by Quinssa."

Individual fans were more critical on social media.

Rob Harding wrote: "Lifelong Sarries fan here. Not a fan of this however. Please back out promptly."

And Quins supporter Sue Harvey wrote: "I don't buy that this is the only way to offer dressing-room tours, a match seat on the bench or attendance at a training session. How about a charity raffle? Or awards for milestone anniversaries of being a season ticket holder?"