In the year before an election, there are limits on how much you can spend on influencing voters. Guidance from the Electoral Commission (pdf) describes the limit for non-party campaigners:
If you are not registered, including if you are not eligible to register, you cannot spend more than £20,000 in England or £10,000 in any of Scotland, Wales or Northern Ireland during a regulated period on regulated campaign activity.
All the money for DontSplitTheRemainVote comes from myself. There are no other donors.
I'm not going to spend anywhere near £20,000! But public campaigns should have public accounts, so here is an breakdown of costs.
The cost is £50.69.
Hosting - original setup of static html with postcodes using php+sqlite:
Hosting - the last month, with postcode lookup using fcgi+postgresql and failover between 2 servers:
I spent money on advertising, a large £679.59. About 10-15% of visitors came from advertising.
Over time I reduced the maximum cost per click to 2p/click and still hit the daily cap on spending every day. I used manual cost per click because the automatic algorithm wanted to spend 70p/click or more (surprise, surprise).
During the regulated period, I spent £730.28 on dontsplittheremainvote.com.