Flipkey, TripAdvisor’s vacation rental unit, is raising the fees it charges property managers, Skift has learned.

Flipkey has several business models for property managers, and those that opt to pay per qualified lead will see the pay-per-lead email rate rise 28.5% to $9, up from $7, and the fee for phone leads has increased 20% to $12, up from $10.

Skift obtained a copy of the rate increase, which applies immediately to new accounts, but will be delayed until January 1, 2015, for existing accounts.

Paying per qualified lead forwarded to vacation rental property managers is one of three Flipkey business models. Owners and managers can alternately choose to pay a commission for confirmed bookings or pay an annual subscription fee in exchange for receiving an unlimited quantity of leads.

In informing property managers about the increase, Flipkey stated, “we do our best to keep prices low. This is the first rate increase in 2 years.”

In trying to sell property managers on the rate hike, Flipkey emphasizes that its “investments in marketing over the past year have doubled traveler inquiries, and we work relentlessly to gain exposure on major search engines to bring in even more travelers in 2015.”

Fkipkey also points out that vacation rentals have been added to the TripAdvisor mobile app.