Online sponsorship sites have been warming up because they're so convenient. It's easy to give, they handle the gift aid and pass the money to your selected charity.
But what most marathon runners don't want is to have their friends' donations overtaken by charges. So it's good that the choice of websites has just expanded.
There's the biggest contender, JustGiving, which charges 5% on donations plus the gift aid.
Virgin Money Giving levies 2% on the donation only.
Bmycharity has no transaction fee.
Nor does the newcomer, MyDonate, just set up by BT.
JustGiving says its 5% is worth it because the site raises more for charity than the others and gives a good service.
But people are likely to ask: why do all this work and use an online fundraising site which charges a percentage fee?
It's worth knowing that all except MyDonate charge the charity as well, either up front or by the month, just for having an account.
Also, there are card processing charges, which you don't seem to be able to escape with any of these four websites.
Preparation isn't just about getting your body ready. It's about making the most of everyone's donations too. So don't trip up over sponsorship.