Additional incentive weekly drawings probably help a bit, but for many players, including myself, that's not overly appealing, since it still involves a delay. Also, a player seeking to spend $20 is mainly interested in hitting a big prize. However, an instant win (via entering code / scanning barcode on lottery website for security reasons) with odds of say 1 in 100 to win $100 instantly for a $20 raffle would be a strong incentive to buy tickets sooner and frequently.
Lotteries would do better to be a bit more generous than not selling out. There's plenty of headroom for additional payouts, since most lottery raffles have overall payouts in the 50% range. Using my example above, 1 in 100 to win $100 instantly would only add 5% to the overall payout leaving plenty of margin for the lottery.
For FL raffle, doing so would add $750,000 cost, which seems a lot, but translates to 37,500 tickets, which is a relatively small fraction. PA raffle would have done far better with showing a count down of tickets remaining / sold from the getgo and having an instant win component, but for some reason, lotteries don't listen to the players and/or believe they know what's best. Not to say instant win is the end all be all for selling raffle tickets, because there are other important considerations, in particular, number of tickets offered, prize structure, and time horizon to the drawing.
As for buying tickets for gifts, I've long felt lotteries promote this wrong. Ideal gift tickets are those with top payouts of $5,000 or less (many $1 tickets fall into this category and are widely available everyday). Less disappointment for the gift giver. Hearing the recipient won $100K, or even a $1 million on a raffle or $5+ instant, would be very upsetting to many. Personally, I rarely give out lottery tickets as gifts, but when I do, it's $1 instant tickets only with low top payouts.
Buying tickets for others is always risky, because if they win the big one, who really owns the rights to the winnings... The person who eventually ends up with the ticket, the original purchaser, or both... Can lead to a long nasty court battle. Best to buy one's own tickets whenever possible unless one is intending (or at minimum, prepared to, if forced) to split the winnings with the buyer. Shame what money does to people, but then one's survival, in developed societies, depends on money; greed is an inherent survival trait that can disrupt even the best of relationships.
G5- if it's feasible, take the drive to FL yourself. Nice scenic route, which adds a little extra distance, but not that much more time, is down I81 to I77 and over to I26 to then meet up with I95 in SC. Bypasses the Baltimore and DC beltways completely. Do some sightseeing, etc while there, and buy the tickets personally. Good luck :)