Hearts say the club's share issue has broken through the £600,000 mark less than a month after making the request.
The Edinburgh club issued a plea for "emergency backing" from supporters three-and-a-half weeks ago to avoid the prospect of administration.
And Hearts praised their fans for responding in such numbers to their current financial plight.
The club said capacity crowds at Tynecastle generates income "that will help us to pay players and staff".
Tynecastle was sold out last weekend, with a crowd of 16,443 for the win over St Mirren.
In a statement on the club's website, Hearts said: "There is still a great deal to be done and we must keep up the good work that is happening in order to maintain our recovery plan and see us through to the end of the season.
"Only with your help will we deliver a positive outlook for the club.
"The next four weeks are crucial now for us to navigate the club into safer waters."
Hearts agreed an extension with Her Majesty's Revenue and Customs that will allow the club further time to pay an outstanding tax bill.
The arrangement allows Hearts to pay the £450,000 bill in two instalments and lifts the immediate threat of closure facing the club.
Supporters' groups have undertaken a number of fundraising activities separate to the share issue.
And Supporters Direct Scotland have been in talks with Hearts in relation to a proposed fan-led takeover to buy out owner Vladimir Romanov.