YouTube beauty vloggers Elle and Blair Fowler announce Skylark cosmetic line, available in September.

The new cosmetic line created by YouTube beauty vloggers Elle and Blair Fowler, “Skylark by Elle and Blair,” was announced Thursday and has generated huge WOM buzz from their highly-engaged fan base.

In a YouTube video posted on Thursday, Blair Fowler announced that presale sign-up for the new line is available now on blush.com, which will be the exclusive distributor of Skylark. Within minutes of the video’s launch, blush.com crashed due to an unprecedented number of site visits—over 10 times the daily average.

“We are thrilled to know that Elle and Blair’s fans are so enthusiastic about Skylark,” said Dan Obegi, CEO of blush.com and DermStore.com. “While we knew they had a devoted following, we could have never imagined numbers like this.”

Skylark by Elle and Blair will be released in September, supporting the release of the sisters’ first novel, Beneath the Glitter, which will be published by St. Martin Press. Skylark by Elle and Blair will release two lip glosses inspired by the novel’s main characters, Sophia and Ava London. The line will continually expand with new products added seasonally.